Early Byzantine Vaulted Construction in Churches of the Western Coastal Plains and River Valleys of Asia Minor 9781407308104, 9781407338019

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BAR S2246 2011 KARYDIS

Early Byzantine Vaulted Construction in Churches of the Western Coastal Plains and River Valleys of Asia Minor Nikolaos D. Karydis

EARLY BYZANTINE VAULTED CONSTRUCTION IN CHURCHES

B A R Karydis 2246 cover.indd 1

BAR International Series 2246 2011 16/06/2011 13:45:29

Early Byzantine Vaulted Construction in Churches of the Western Coastal Plains and River Valleys of Asia Minor Nikolaos D. Karydis

BAR International Series 2246 2011

Published in 2016 by BAR Publishing, Oxford BAR International Series 2246 Early Byzantine Vaulted Construction in Churches of the Western Coastal Plains and River Valleys of Asia Minor © N D Karydis and the Publisher 2011 The author's moral rights under the 1988 UK Copyright, Designs and Patents Act are hereby expressly asserted. All rights reserved. No part of this work may be copied, reproduced, stored, sold, distributed, scanned, saved in any form of digital format or transmitted in any form digitally, without the written permission of the Publisher.

ISBN 9781407308104 paperback ISBN 9781407338019 e-format DOI https://doi.org/10.30861/9781407308104 A catalogue record for this book is available from the British Library BAR Publishing is the trading name of British Archaeological Reports (Oxford) Ltd. British Archaeological Reports was first incorporated in 1974 to publish the BAR Series, International and British. In 1992 Hadrian Books Ltd became part of the BAR group. This volume was originally published by Archaeopress in conjunction with British Archaeological Reports (Oxford) Ltd / Hadrian Books Ltd, the Series principal publisher, in 2011. This present volume is published by BAR Publishing, 2016.

BAR PUBLISHING BAR titles are available from:

E MAIL P HONE F AX

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To Karolina, Io, Alex, and Dimitris

Contents

List of Illustrations

IX

Acknowledgements

XV

Abstract

XVII

Introduction

1 1. An Outline of the Monuments and their Bibliography Overview Saint Mary at Ephesos St John at Ephesos Building D at Sardis St John at Philadelphia The Vaulted Basilicas of Hierapolis, Priene, and Pythagorion

3 3 4 8 13 16 18

2. Methodology

23

Part 1

The Surviving Structure: Materials and Techniques

25

Chapter 1

Building Materials

27

1. Fired Brick

27

Introduction The Use of Brick in Walls and Supports The Use of Brick in Arches and Vaults The Reuse of Bricks Early Byzantine Brick Making Brick Sizes 2. Dressed Stone and Marble

27 27 28 28 29 30 32

Introduction Structural Uses of Dressed Stone and Marble The Use of Marble The Use of Spolia Types of Stone and Marble and their Origins 3. Rubble

32 32 35 39 42 45

The Use of Rubble The Nature and Shape of Rubble 4. Mortar

46 47 47

Types of Lime Mortar Mortar Production

48 49

V

Chapter 2

The Load Bearing Structure

51

1. Introduction

51

2. Rubble Masonry

51

Introduction Types of Rubble Masonry and Mortared Rubble Brick Masonry Bands Case Studies 3. Solid Brick Masonry

51 52 53 53 54

Construction Principles Case Studies: St. Mary and St. John at Ephesos 4. Ashlar Masonry

55 56 57

Construction Methods Ashlar Masonry Piers Ashlar Masonry Walls and Pilasters Patterns of Development

58 60 62 62

5. Internal Colonnades

63

Part 2

The Vaulted Structure

67

Chapter 3

The Vaults of St. John the Theologian at Ephesos

69

1. Introduction

69

2. Analysis Of Vault Fragments

69

Vault Fragment A Vault Fragment B Vault Fragment C Vault Fragment D Vault Fragments Recorded in the Photographic Survey of 1951 Vault Fragments from the Baptistery and the Skeuophylakion Conclusions from the Examination of Vault Fragments 3. Documentary Evidence

72 75 78 80 81 83 84 85

Ibn Battuta Georgios Tornikes Procopius Conclusions from the Examination of Literary Sources 4. Comparable Examples

85 85 85 87 88

Spherical Vaults in Hagia Sophia and St. Eirene Domes with Arched Brick Courses: from Side to Spalato The Secondary Vaults of St. Eirene and Basilica B at Philippi Gallery Vaults in the Aegean Coastlands and Constantinople 5. Previous Reconstructions

88 92 93 98 100

Emphasis on Geometry and Form The Focus on Uniformity Consistency with Early Byzantine Vaulting Practice Conclusion

VI

100 100 100 101

6. Graphic Reconstruction

101

Primary Vault System Secondary Vault System

Chapter 4

101 105

The Vaults of Building D at Sardis

107

1. Analysis of Vault Fragments

107

Vault Fragment A The Vault Core

111 112

2. Oblong Bays and Spherical Vaults

113

3. Reconstruction of the Vaulted Structure

114

Broad Arches Pendentives

Chapter 5

114 115

The Vaults of St. John the Theologian at Philadelphia (Alaúehir)

117

1. Introduction

117

2. Analysis of Vault Fragments

117

Broad Arch Fragments Pendentive Fragments The Vault Core The Remains of the External Vault Facing 3. Reconstruction of the Vaulted Structure Arches and Pendentives The Facing of the Vaults and the Reconstruction of the Elevations The Central Vaults

Chapter 6

120 122 126 126 127 127 127 129

The Vaults of St. Mary at Ephesos

135

1. Introduction

135

2. An Overview of the Vault Fragments

135

3. The Vaults of the 1st Building Phase

138

The Vaults of the Side Chambers of the Early Church Staircase Vaults The Vaults of the Baptistery 4. Secondary Vaults of the Cross-Domed Church The Vaults in the Side Chambers The Broad Arches 5. Reconstruction of the Cross-Domed Church Nave Vaults Secondary Vaults Discussion

138 139 142 147 147 148 150 151 151 151

VII



 6. Development of Vaulting Techniques 

The Changing Dimensions of Bricks and Mortar Beds Brick Layout in Vaults: from Invention to Standardisation Origins of Vaulting Techniques

152 153 153 153





Chapter 7

 

Typology of Brick Vaults

155

1. General Considerations

155

2. Vaults and with Radial Brick Courses: the Primary Vault Structure

155

Broad Arches and Barrel Vaults built with Bricks Set Radially Pendentives and Spherical Vaults built with Bricks Set Radially

156 161







3. Vaults with Pitched Bricks: the Secondary Vault Structure



Pitched-brick Barrel Vaults Pitched-brick Domical Groin Vaults

165 166 168





4. Vaults with Arched Brick Courses



Barrel Vaults with Arched Brick Courses Spherical Vaults with Arched Brick Courses

206 170 170





Conclusions



173 1. The New Reconstruction Methodology



St. John at Ephesos Building D at Sardis St. John at Philadelphia St. Mary at Ephesos



173 173 176 176 177

2. Principles of Vaulted Construction

177

Building Materials Load Bearing Systems Vault Typology and Construction

177 178 179









Appendix

181

Bibliography

183

Index

187



         

VIII

List of Illustrations

17. Philadelphia, St. John, view of northeast pier from the north, showing detail of external facing.

All the photographs have been taken by the author. For the drawing credits, see the list below.

18. Philadelphia, St. John, view of southwest pier, with the remains of the wall that enveloped the nave visible in the foreground. 19. Hierapolis, Urban Basilica, view of the nave looking east. 20. Hierapolis, Urban Basilica, reconstructed plan (drawing by Karolina Vasilikou, 2009). 21. Hierapolis, extramural “Church of the Thermae”. The late Roman piers and stone voussoir arches can be seen in the foreground. 22. Hierapolis, “Church of the Thermae”, schematic plan showing the early Byzantine additions (hatched) to the late Roman structure, during its conversion to a church (sketch by Nikolaos Karydis, 2004).

Introduction 1. Comparative plans of the main vaulted churches of west Asia Minor: a. St. Mary at Ephesos, b. St. John at Ephesos, c. ‘Urban Basilica’ at Hierapolis, d. St. John at Philadelphia, e. Building D at Sardis (drawing by Karolina Vasilikou, 2009).

23. Priene, Early Byzantine Basilica south of the Theatre. View of the nave looking west. 24. Priene, Early Byzantine Basilica, nave pier and detail of pedestal.

2. Map of west Asia Minor showing the sites of the main early Byzantine vaulted churches.

25. Pythagorion, Samos, “Tria Dontia” Basilica, reconstructed plan showing the main phases as identified by the author (drawing by Nikolaos Karydis, 2008).

3. Ephesos, St. Mary, view of the east apse. 4. Ephesos, St. Mary, cross-domed church, view of the northeast pier.

26. Pythagorion, “Tria Dontia” Basilica, view of the three major buttresses.

5. Ephesos, Baptistery of St. Mary, overall view with the atrium of the church in the background.

27. Pythagorion “Tria Dontia” Basilica, panoramic view of the internal colonnades.

6. Ephesos, St. Mary, general layout plan showing the main building phases as identified by F. Knoll (drawing by Karolina Vasilikou, 2009).

Chapter 1

7. Ephesos, St. John the Theologian, plan of Justinian’s church at ground level, showing main phases (drawing by Karolina Vasilikou, 2009).

28. Ephesos, St. John, chancel. Detail of brick masonry wall.

8. Ephesos, St. John, general view of the remains from the chancel.

29. Ephesos, St. Mary, cross-domed church. View of pier faced with brick masonry.

9. Ephesos, St. John the Theologian, central Bema and restored Synthronon.

30. Ephesos, St. John, chancel. Detail of relieving arch. 31. Hierapolis, “Urban Basilica”. View of the debris inside the nave, showing traces of brick structure.

10. St. John at Ephesos, Baptistery, remains of internal nucleus looking west, with the restored colonnade in the background.

32. Ephesos, St. Mary, cross-domed church. Detail of apse wall with bricks of different colour and size.

11. St. John at Ephesos, Skeuophylakion, detail of the central piers.

33. Sardis, Building D, detail showing bricks that have probably fallen from the vaults.

12. Sardis, Building D, view of southwest pier from the southeast.

34. Ephesos, St. John. Detail of vault fragment A exhibiting finger marks on the brick surfaces.

13. Sardis, Building D, reconstructed plan (drawing by Karolina Vasilikou, 2009).

35. Philippi, Basilica B, brick fragment with finger marks on its surface.

14. Sardis, Building D, view of southeast pier, showing detail of external wall facing.

36. Ephesos, baptistery of St. Mary, detail of pier facing. 37. Ephesos, St. John, cornice fragments with various profiles.

15. Philadelphia, church of St. John, view of northeast pier from the southwest.

38. Ephesos, St. Mary, inner face of the external ashlar masonry walls.

16. Philadelphia, St. John, reconstructed plan (drawing by Karolina Vasilikou, 2009).

IX

40. Ephesos, St. Mary. View of the early Christian quadriporticus showing the remains of the surrounding colonnade.

61. Ephesos, St. John, axonometric of typical brick masonry wall (cf. fig. 60), showing revetment fragment found by G. A. Sotiriou, 1924 (drawing by Nikolaos Karydis, 2007).

41. Ephesos, St. John, detail of pier facing exhibiting holes for the fixing of marble revetment.

62. Ephesos, St. Mary, cross domed church. View of the southeast pier from the nave.

42. Ephesos, St. Mary, view of the door leading from the quadriporticus to the narthex, looking east.

63. Three ways to lift a stone block. From left to right: with the aid of tenons (handling bosses); using grips (iron forceps); by creating a handle on its top surface using a lewis (sketch by Nikolaos Karydis, 2009).

39. Ephesos, St. John. View of the transept.

43. Samos, Pythagorion, “Tria Dontia” Basilica. View of the south wall showing an unorthodox reuse of column drums.

64. Hierapolis, “Urban Basilica”, axonometric of typical nave pier (drawing by Nikolaos Karydis, 2008).

44. Ephesos, St. Mary, south side chamber of the early basilica. The north wall incorporates a ceiling coffer.

65. Philadelphia, St. John, axonometric drawing of the northwest pier, showing core and facing (drawing by Nikolaos Karydis, 2008).

45. Ephesos, St. Mary, cross-domed church. Detail of pier facing that exhibits a reused chancel slab.

66. Ephesos, St. John, axonometric of typical pier showing the connection between pilaster and main pier in four different horizontal sections (drawing by Nikolaos Karydis, 2008).

46. Ephesos, St. John. Detail of pier facing with some of its stone blocks displaying anathyrosis, redundantly arranged lewis marks and dentils. 47. Philadelphia, St. John, view of the northwest pier from the southeast, showing a cornice consisting of heterogeneous stone blocks.

67. St. John at Philadelphia. Interpretive axonometric drawing of the northeast pier showing the ashlar masonry facing, the mortared rubble core, and the wall that originally enveloped the building (drawing by Nikolaos Karydis, 2008).

48. Ephesos, St. John. The three different types of stone used in the pier facings.

68. Ephesos, St. John, transept, remains of the northwest pier. Dressed stone is used almost throughout the pier mass.

49. Ephesos, St. John. The three different varieties of Proconnesian marble used in the column shafts. 50. Ephesos, St. John. Detail of capital made of white marble with light grey veins.

69. Priene, Temple of Athena Polias (late 4th century B.C.). Detail of ashlar masonry retaining wall of the podium on which the building rests.

51. Ephesos, St. Mary, detail of Breccia column shaft. 52. Ephesos, St. John, nave, detail of pier revealing the use of rubble in its core.

70. Ephesos, St. John, Transept. View of southeast colonnade, showing details of stylobate, column bases, monolithic column shafts, and capitals.

53. Sardis, Building D. Southwest pier viewed from the east.

71. Ephesos, St. John, detail of stylobate with dowel hole.

54. Ephesos, St. John, view of one of the south buttresses, displaying mortar joints of various thicknesses.

72. St. John at Ephesos, Transept. Detail of typical, Ionicstyle column base.

55. Sardis, Building D, exposed inner layer of the pier structure.

73. Constantinople, Hagia Sophia. Schematic drawing illustrating the seating of column shafts on lead sheets (Q) and the use of bronze collars (F) to contain the lead (drawing by Nikolaos Karydis, 2004, after A. Choisy, 1883).

56. Ephesos, St. Mary, early Christian basilica, detail of the north flank of the apse exhibiting mortared rubblework.

74. Ephesos, St. John. Detail of Ionic-style impost capital (upside down).

Chapter 2 57. Ephesos, St. Mary, Narthex. Axonometric view of rubble masonry wall, showing the use of thin stone slabs (drawing by Nikolaos Karydis, 2007).

Chapter 3 75. Ephesos, St. John the Theologian, view of vault fragment A looking south.

58. Ephesos, St. John, transept wall. Detail of rubble and brick masonry wall.

76. View of vault fragment B.

59. Priene, Basilica, view of rubble masonry walls.

77. View of vault fragment C looking north.

60. Ephesos, St. John, chancel. Detail of south wall made of brick masonry set on a stone stylobate. Cavities such as the one in this wall resulted from the use of timber scaffolding during construction.

78. View of vault fragment D looking north. 79. Detail of vault fragment A, showing remains of broad arch consisting of two arch-rings.

X

80. Detail of vault fragment A, showing remains of supporting arch, and pendentive.

pendentives and broad arches (drawing by Nikolaos Karydis, 2009). 102. Constantinople, St. Eirene, schematic axonometric of the springing of the same pendentive dome as in figure 100 (drawing by Nikolaos Karydis, 2009).

81. Vault fragment A, view from the top. 82. Vault fragment A. Reconstructed axonometric view from above (drawing by Nikolaos Karydis, 2008).

103. Constantinople, St. Eirene, schematic axonometric of the springing of the pendentives of the central dome (drawing by Nikolaos Karydis, 2009).

83. Vault fragment A. Reconstructed axonometric view from below (drawing by Nikolaos Karydis, 2008). 84. Vault fragment B, view from the west. Detail of the convergence of two broad arches, showing the springing of a pendentive between them.

104. Constantinople, Hagia Sophia, view of the gallery.

85. Vault fragment B. Reconstructed axonometric view from above (drawing by Nikolaos Karydis, 2008).

105. Side (South Asia Minor), East Mausoleum, reconstructed cut-away axonometric (drawing by Nikolaos Karydis, 2010).

86. Vault fragment B. Reconstructed axonometric view from below (drawing by Nikolaos Karydis, 2008).

106. Constantinople, St. Eirene, aisle vaults, cut-away axonometric (drawing by Nikolaos Karydis, 2008).

87. Vault fragment B. Remains of mosaic with white and blue-green tesserae.

107. Philippi, Basilica B, view of north aisle looking west.

88. Vault fragment C. View from the southeast, showing remains of supporting arches (with double arch-rings) and vault core.

108. Philippi, Basilica B, aisle vaults, reconstructed cutaway axonometric based on the extant remains shown with a grey outline (drawing by Nikolaos Karydis, 2008).

89. Vault fragment C. Reconstructed axonometric view corresponding to the view of figure 88 (drawing by Nikolaos Karydis, 2008).

109. Philippi Basilica B, detail of aisle vault fragments showing remains of gallery floor consisting of spoliated stone members.

90. Vault fragment C, view from the northwest.

110. Ephesos, St. John the Theologian, nave, south colonnade and aisle vaults, mid-20th century partial restoration.

91. Hypothetical reconstructed axonometric view of vault fragment C and its immediate surroundings from below (drawing by Nikolaos Karydis, 2008).

111. Constantinople, Sts. Sergios and Bakchos, cut-away axonometric (drawing by Nikolaos Karydis, 2006).

92. Vault fragment D, view from the southwest. 93. Vault fragment D. Reconstructed axonometric view from below (drawing by Nikolaos Karydis, 2008).

112. Ephesos, St. John the Theologian, west cross arm (nave), pendentive domes, reconstructed axonometric. This hypothetical reconstruction is based on fragments recorded by H. Hörmann in 1951 (drawing by Nikolaos Karydis, 2008).

94. Axonometric of the four arches surrounding the west bay of the church (drawing by Nikolaos Karydis, 2009). 95. Ephesos, St. John the Theologian, Axonometric diagram of the four arches of figure 94 after the addition of pendentive borders (drawing by Nikolaos Karydis, 2009).

113. Nave, pendentive dome, alternative reconstruction (drawing by Nikolaos Karydis, 2008).

96. Ephesos, St. John the Theologian, view of the narrow corridor between the transept and the baptistery complex, showing a barrel vault consisting of two rings of bricks set radially.

116. Ephesos, St. John the Theologian, transept, reconstructed axonometric of the aisle vaults, showing diagonal intersection between barrel vaults.

115. Transept, typical aisle vault, reconstructed axonometric (drawing by Nikolaos Karydis, 2009).

97. Ephesos, St. John the Theologian, Skeuophylakion, entrance hall.

Chapter 4

98. Ephesos, St. John the Theologian, Baptistery, southeast ancillary chamber. Remains of groin vault.

117. Sardis, Building D, view of southeast pier from the north.

99. Ephesos, St. John the Theologian, view of the south colonnade of the nave. The imperial monograms of Justinian and Theodora can be distinguished on the faces of the ionic impost block capitals.

118. Sardis, Building D, southeast pier, elevation (drawing by Nikolaos Karydis, 2008). 119. Interpretive axonometric of the southeast pier (drawing by Nikolaos Karydis, 2008).

100. Constantinople, St. Eirene. Cross-section of the pendentive dome over the west bay of the nave, showing the interface (A) between dome and broad arches (drawing by Nikolaos Karydis, 2009).

120. Vault fragment A, reconstructed north elevation superimposed on the photograph of the remains (drawing by Nikolaos Karydis, 2009).

101. Constantinople, St. Eirene, cross-section of the central dome, showing the interface (B) between

XI

121. Vault fragment A, reconstructed west elevation, superimposed on the scaled photograph of the remains (drawing by Nikolaos Karydis, 2009).

140. Philadelphia, St. John, reconstructed, cut-away axonometric (drawing by Karolina Vasilikou and Nikolaos Karydis, 2009).

122. Vault fragment A, detail of northwest corner.

141. Philadelphia, St. John, cut-away axonometric. Reconstruction with two domical vaults (drawing by Nikolaos Karydis, 2009).

123. Vault fragment A. View from the southeast with detail of external facing of rubble and brick masonry.

142. Philadelphia, St. John, cut-away axonometric. Alternative reconstruction showing composite vaulting scheme (drawing by Nikolaos Karydis, 2009).

124. Reconstructed, cut-away axonometric of southeast pier, showing supporting arches, pendentive border, and quarter of domical vault (drawing by Nikolaos Karydis, 2009). 125. Sardis, Building D, reconstructed axonometric (drawing by Nikolaos Karydis, 2009).

Chapter 6 143. Ephesos, St. Mary, view of the remains from the narthex looking east.

Chapter 5 126. Philadelphia, St. John, northeast pier. Detail of arch and pendentive remains.

144. Ephesos, St. Mary, overall view of the remains from the chamber south of the great apse looking northwest.

127. Philadelphia. St. John. View of northeast pier from the west with vault fragment A on the top.

145. Early, columnar basilica, north side chamber, southwest corner.

128. View of northwest pier from the south, showing vault fragment B.

146. View of the baptistery of St. Mary looking northwest.

129. Northwest pier, detail of pendentive fragment.

147. Ephesos, St. Mary, cross-domed church, south side chamber (inside the pier) looking west.

130. Reconstructed north elevation of northeast pier and its adjoining arch (drawing by Nikolaos Karydis, 2009).

148. Ephesos, St. Mary, columnar basilica, south side chamber. Detail of corner buttress with a recessed profile.

131. Reconstructed north elevation of northwest pier and its adjoining arch superimposed on photograph of the remains, as in fig. 130 (drawing by Nikolaos Karydis, 2009).

149. Ephesos, St. Mary, columnar basilica, north side chamber, fragment of pendentive dome. 150. Ephesos, St. Mary, columnar basilica, north side chamber. Interpretive axonometric diagram of spherical vault with radiating arched courses (drawing by Nikolaos Karydis, 2009).

132. Reconstructed south elevation of northwest pier, superimposed on photograph of the remains as in the two previous figures (drawing by Nikolaos Karydis, 2009).

151. St. Mary, columnar basilica, reconstructed, cut-away axonometric of the north side chamber showing peculiar pendentive dome structure (drawing by N. Karydis, 2009).

133. Interpretive axonometric of northwest pier (drawing by Nikolaos Karydis, 2009). 134. View of vault fragment B, showing pendentive detail.

152. St. Mary, columnar basilica, reconstructed sections of the north side chamber showing pendentive dome built with arched brick courses (drawing by Nikolaos Karydis, 2009).

135. Northeast pier, vault fragment A. Detail of pendentive on the southwest corner of the fragment. 136. Diagram illustrating the problematic connection between the arches springing from the northwest pier and a hypothetical pendentive with a precise, spherical shape (drawing by Nikolaos Karydis, 2009).

153. St. Mary, columnar church, south side chamber. Detail of the shallow barrel vault covering the south staircase, looking north. 154. St. Mary, columnar basilica, reconstructed axonometric drawings of the staircase vaults (drawings by N. Karydis, 2009).

137. Reconstructed plan of the pendentive on top of northwest pier (drawing by Nikolaos Karydis, 2009).

155. St. Mary, columnar basilica, north staircase. Detail of shallow barrel vault with a “herringbone” brick pattern.

138. Northeast pier, view from the southeast, showing remains of external façade.

156. Baptistery of St. Mary, view of vault fragment ‘A’ from the north.

139. Philadelphia, St. John, reconstructed axonometric showing the north elevation of the church (drawing by Nikolaos Karydis, 2009).

157. Baptistery of St. Mary, view of vault fragment ‘A’ from the southeast.

XII

1990, p. 82), south side chamber. Detail of pendentive remains, based on photographs published in R. Cormack, 1990 (sketch by Nikolaos Karydis, 2006).

158. Baptistery of St. Mary, detail of vault fragment B, showing remains of a barrel vault with a pitched brick structure. 159. Baptistery of St. Mary, view of vault fragment D. 160. Baptistery of St. Mary, hypothetical reconstruction of the dome on the basis of fragments recorded by F. Knoll, 1932 (drawing by Nikolaos Karydis, 2009). 161. Baptistery of St. Mary, reconstructed axonometric (drawing by Nikolaos Karydis, 2009). 162. St. Mary, cross-domed church. Detail of the pitchedbrick vault of the north side chamber. 163. St. Mary, cross-domed church, northeast pier and side chamber. Cut-away axonometric showing various barrel vaults (drawing by Nikolaos Karydis, 2009). 164. St. Mary, cross-domed church, view of barrel vaults. 165. Ephesos, St. Mary, cross-domed church. Interpretive axonometric of the barrel vaults over the passageways of the west piers (drawing by Nikolaos Karydis, 2009). 166. Ephesos, St. Mary, cross-domed church. Reconstructed cut-away axonometric (drawing by Karolina Vasilikou, 2009).

Chapter 7 167. St. Mary, cross-domed church, southwest pier, typical barrel vault with radial brick courses (drawing by Nikolaos Karydis, 2009). 168. Ephesos, St. John, detail of barrel vault. 169. Sardis, Gymnasium, broad arch consisting of two superimposed rings of radial bricks. 170. Interpretive model simulating barrel vault construction and showing the form of centering used in the radial setting of bricks (model by Nikolaos Karydis, 2003–4). 171. Miletus, Baths of Faustina (2nd Century A.D.). Detail of lateral niches, showing barrel vaults made of flat chips of stone set radially.

178. St. Mary at Ephesos, cross-domed church, east side chambers, typical barrel vault built with pitched bricks (sketch by Nikolaos Karydis, 2006). 179. Interpretive sections and plans showing a stage in the construction of two typical pitched brick barrel vaults (sketch by N. Karydis, 2004, after A. Choisy, 1883). 180. Constantinople, Hagia Sophia, outer narthex, pitched-brick barrel vaults. 181. Ephesos, St. Mary, columnar basilica, south side chamber, barrel vault with arched brick courses (drawing by Nikolaos Karydis, 2009). 182. Ephesos, St. John, nave, reconstruction of spherical vault built with arched brick courses (drawing by Nikolaos Karydis, 2009).

Conclusions 183. Ephesos, St. John. Table showing pendentive fragments A, B, and C, and their current location in the site (drawings by Nikolaos Karydis and Karolina Vasilikou, 2009). 184. Ephesos, St. John the Theologian, reconstructed axonometric (drawing by Karolina Vasilikou and Nikolaos Karydis, 2009). 185. Ephesos, St. John the Theologian, pre-Justinianic church and baptistery, reconstructed plan. 186. Sardis, Building D, reconstructed axonometric (drawing by Nikolaos Karydis, 2009). 187. Philadelphia, St. John, reconstructed axonometric (drawing by Karolina Vasilikou and Nikolaos Karydis, 2009). 188. Hierapolis, “Urban Basilica”, view of the south external wall. 189. Hierapolis, “Urban Basilica”, view of the remains of the main piers.

172. Miletus, Baths of Faustina. Detail of barrel vault with stones set radially.

190. Ephesos, St. John, transept, view of the south aisle, illustrating the composite character of the load bearing system.

173. Sardis, Building D, hypothetical Reconstruction. Detail of typical spherical vault with bricks laid radially (drawing by Nikolaos Karydis, 2009).

Appendix

175. Sardis, Bath-Gymnasium Complex, hall “BHC” (2nd century A.D. and later). Detail of pendentive remains on northwest corner.

191. Philadelphia, St. John, northeast pier. Cut away axonometric showing the springing of the pendentive (drawing by Nikolaos Karydis, 2009).

174. Rome, Baths of Caracalla (3rd Century A.D.), octagonal Nymphaeum. 176. Ravenna, “Mausoleum of Galla Placidia”, interior view looking towards the pendentive dome. 177. Aphrodisias, early Byzantine basilica (probably middle of the 5th century according to R. Cormack,

192. Sardis, Building D, southeast pier. Reconstructed axonometric showing the lower part of the pendentive (drawing by Nikolaos Karydis, 2009). 193. Sardis, Building D, southeast pier, diagrammatic plan of the springing of the pendentive (sketch by Nikolaos Karydis, 2009).

XIII

XIV

Acknowledgements

I started exploring the architectural history of west Asia Minor in 2003, after reading Auguste Choisy’s book “L’ Art de Bâtir chez les Byzantins”. I was then a student of Architecture, working for my lecture thesis in the library of the Archaeological Society in Athens, and my admiration for Choisy’s axonometric drawings made me overlook the important difficulties of the project that was later to become the focus of my doctoral research. The realisation of this project, which resulted in the present book, would not have been possible without the contribution of a number of people to whom I would like to express my gratitude.

Many people contributed to my thoughts and ideas about early Byzantine construction. I would particularly like to thank Mark Wilson Jones, my supervisor, for his support during these years, and for helping me in the interpretation and evaluation of the churches I investigated. My heartfelt thanks also go to my teachers in the National Technical University of Athens, Professors Charalambos Bouras and Panagiotis Touliatos who provided the intellectual grounding to tackle the problems that interest me. I also benefited from the conversations I had with Dame Averill Cameron and Prof. Hans Buchwald.

Some of the major complications for a project like this one are related to the difficulty of access to the monuments. I am indebted to my father, Dimitris Karydis, for all his support during our travels in April 2007 and June 2008, and for being constantly on my side. I would also like to thank Prof. Dr. Machiel Kiel, our companion during the first visit to west Turkey, for his guidance and encouragement.

One of the major contributions in my study of the monuments came from my mother, Alex Avieropoulos Karidis, who patiently translated most of the extensive German literature on the monuments of Ephesos for me. Her hand-written drafts, full of personal observations, have been one of the main sources of knowledge during my research. Crucial financial support for this research came from the Greek Institute of state scholarships (I.K.Y.), the same institute that funded my MSc studies. I hope that the fellowship I was generously offered, while held by more distinguished researchers, may perhaps be judged in the future to be not ignobly given to the author of this dissertation.

My visit to the monuments would not have been as fruitful and stimulating without the hospitality of the archaeological teams carrying out fieldwork in them. I am indebted to Ms Kathy Kiefer for our enlightening conversation about Building D at Sardis, and for making surveys of the monument available to me. I will always remember the stimulating conversations I had with Prof. Nick Cahill, Field Director of the Archaeological Expedition to Sardis, and with Prof. Marcus Rautman, who guided me to the late Antique monuments of Sardis. I would also like to thank Dr. Mustafa BüyükkolancÕ for sharing with me his insights about the churches of Ephesos during our meeting in Ephesos Museum in April 2007.

Finally, I would like to express my gratitude to my companion, Karolina Vasilikou, who, sacrificing many hours of her time, helped me with every single aspect of the present research. She has been next to me from its beginning, in 2003, accompanying me in my site visits, helping in the survey of the buildings, reading drafts of my dissertation, and carrying out a series of drawings that form a crucial part of the present book.

XV

XVI

Abstract

The churches of St. John and St. Mary at Ephesos, ‘Building D’ at Sardis, St. John at Philadelphia, and the basilicas of Hierapolis illustrate the development of vaulted construction in the west coast of Asia Minor between the 5th and the 7th century AD. These churches, due to their dilapidated condition, constitute ideal sources of information about the materials and construction techniques employed in some of the most important building programs of the early Byzantine Empire. The ruined state of the monuments and the lack of written records have hindered attempts to reconstruct their original form. Although the surviving load-bearing elements of most of the churches have been very well documented, the potential of their remains to offer information about the nature of vaults has not yet been fully appreciated. As a result, the vaulting practices of west Asia Minor remain enigmatic, though they clearly influenced the early development of Byzantine church architecture. The constructional analysis of these churches, along with the reconstruction of their vaults, constitutes the main thrust of the present study. The author’s new documentation

of their structural fabric, carried out in the field during 2007 and 2008, concentrates on the recording of a series of unexplored vault fragments and construction details. The graphic investigation of this evidence, aided by interpretation on the basis of formal comparisons, leads to reasoned revised reconstructions of each church. The resulting reconstruction drawings form the basis for the exploration of some of the most interesting early Byzantine vaulting patterns. Continuing efforts initiated by A. Choisy more than a century ago, this leads to a new typology of vault structures for the region. The latter embraces the structural tissue of vaults, and, thus, hopes to go beyond classifications based solely on geometrical forms, which are too restrictive to respond to the wide variety of solutions found in the region. This book reveals the diversity, elegance and sophistication that characterize some of the most important early Byzantine churches. The analytical study of these monuments highlights the role of the cities of west Asia Minor as centres for experimentation in the field of vaulted construction during the first centuries of the Byzantine period.

XVII

XVIII

I propose to approach this complex subject by exploring two main topics. The first part of the book documents the surviving structures, whereas the second part reconstructs their missing vaults in an effort to visualise the original form of the churches. The opening chapters focus on the nature of the building materials, and the specific building logic that guided their choice and use. This is closely related with the investigation of construction techniques employed in the load bearing elements, substantial parts of which survive and expose their inner structural fabric. Vaulting techniques are explored in the second part of this book. With most of the vaults missing, this exploration presents us with serious difficulties. The only way to study the vaults is through graphic reconstruction on the basis of limited archaeological remains. This study prepares us for the typological classification of vaults in a way that reflects early Byzantine constructional logic. These two topics: the documentation of the surviving structures and the reconstruction of the missing vaults, may be metaphorically regarded as the two “books” of Early Byzantine vaulted construction in west Asia Minor.

Introduction

The sites of Ephesos, Priene, Sardis, Philadelphia, and Hierapolis preserve the ruins of eight churches that reflect the important development of vaulted construction in the west coasts of Asia Minor during the last centuries of the early Byzantine period.1 The construction methods employed in these churches have not yet been investigated as an autonomous topic. Still, their study promises to shed light on one of the most intriguing developments in the history of Byzantine architecture: the break with the tradition of the timber-roof basilica and the passage to vaulted church construction. Indeed, with our knowledge of early Byzantine vaulted construction based mostly on the documentation of Constantinopolitan monuments, our understanding of this major development and the technology associated with it remains partial. This lacuna also deserves filling on account of the inherent significance of several of the monuments of west Asia Minor, beside the fact that, from the 5th to the 7th century, this region was one of considerable creative energy, and by no means a pale provincial shadow of Constantinople.2

Of these two “books”, the one with the most important contribution to the study of early Byzantine architecture is the one devoted to the reconstruction and analysis of vault structures. Indeed, the examination of individual monuments in the second part of the book reveals new evidence for reconstruction that previous fieldwork had overlooked. It thus sheds light on the lesser-known part of the structure of four of the most important churches of the region: their vaults. This is no small lacuna. The structure of vaults is not only fundamental to the character and symbolic potential of Byzantine monuments, but also affected the design and construction methods followed in all their components.3

The purpose of this book is to investigate the materials, structural systems, and vaulting patterns that characterize early Byzantine church construction in the region. The question of how the vaulted churches of west Asia Minor were built is interwoven with the question of how they originally looked like. The advanced dilapidation of the monuments and the disappearance of their vaults hinder both their visualisation and the study of their structure. Most of their remains present us with nothing more than gigantic masses of masonry, often without a discernible shape. The absence of documentary evidence further obstructs the reconstruction of the original forms. In spite of these problems, I am convinced that these lumps of masonry still conserve the potential to convey information about the sophisticated building practices and technology that aided in the creation of some of the earliest vaulted churches. The task of decoding this information from ruined and sometimes scattered remains constitutes the major challenge of this research.

The reconstructions presented in chapters 3, 4, 5 and 6, create a new window into the complex vault forms employed in west Asia Minor during the early Byzantine period. They also suggest a new approach to early Byzantine vaulting. Our perception of vaults is often limited to the observation of their geometrical form. In this book, on the other hand, I focus on their inner structure, looking at it from the lens of a surgeon. Following the example of A. Choisy (1883), I try to explore the principles that guided the setting of brick on brick to form magnificent shells similar to the ones of Hagia Sophia and St. Eirene at Constantinople. Before we move on to further analyse these topics, a few preliminary words are necessary for the monuments on the survey of which the present work is based, and for their bibliography. My own on-site observation of these monuments is often combined with those of others to provide a synthetic study of construction techniques in west Asia Minor. Information about the monuments that constitute our main sources of knowledge and a review of their literature can be found in what follows.

1 For an examination of the Byzantine architecture from the mid-5th to the early 7th century as an autonomous topic under the title ‘early Byzantine building’, see R. Krautheimer (1986, pp. 201–283). 2 For the possible role of west Asia Minor as a generator of architectural forms see H. Buchwald (1984), pp. 209 – 215. This work, which includes further references, seems to supersede the influential publications of A. Choisy (1883, pp. 162–169), and J. Strzygowski (1903). The latter make broad definitive statements on the subject which may be stimulating, but lack adequate substantiation.

3 An example of how vaulting influenced the design of Hagia Sophia’s load bearing structure can be found in R. Mainstone (1988, p. 178).

1

Early Byzantine Vaulted Construction in the Western Coastal Plains and River Valleys of Asia Minor

1. Comparative plans of the main vaulted churches of west Asia Minor: a. St. Mary at Ephesos, b. St. John at Ephesos, c. ‘Urban Basilica’ at Hierapolis, d. St. John at Philadelphia, e. Building D at Sardis (drawing by Karolina Vasilikou, 2009).

2

d.

Introduction

1. An Outline of the Monuments and their Bibliography The remains of at least eight vaulted early Byzantine churches have been recorded in the west coastal plains of Asia Minor and their vicinity (fig. 1). The following list includes the church remains in the region for which a reconstruction with vaulted roofs and an early Byzantine dating (5th–7th century AD) seem plausible: ƒ ƒ ƒ ƒ ƒ ƒ ƒ ƒ

Saint Mary, Ephesos (Domed Phase) Saint John the Theologian, Ephesos Building D, Sardis Saint John (?), Philadelphia (Alaúehir) Urban Basilica, Hierapolis Church of the Thermae, Hierapolis Urban Basilica, Priene “Tria Dontia” Basilica, Pythagorion, Samos

Most of these monuments are found within a limited geographical area: the one defined by the valleys of the rivers Hermos, Kaystros, and Meander, and their deltas (fig. 2). Hierapolis, in the Byzantine province of Phrygia, and Pythagorion, on the island of Samos, lie in the vicinity of this region. In the early Byzantine period, several of these cities had an important administrative role. Ephesos, Sardis and Hierapolis were the capitals of the neighbouring Early Christian provinces of Asia, Lydia, and Phrygia respectively. The b. geographical position of these sites must have also been very important, as the natural point of convergence between the land routes of central Asia Minor and the sea routes through the Aegean Sea.4 This position controlled the passage from the Aegean to the Anatolian plateau and the south coasts of Asia Minor.5 In addition, the cities of this region were surrounded by a countryside richly endowed with natural resources.6

2. Map of west Asia Minor showing the sites of the main early Byzantine vaulted churches. have added several complications in the creation of complex vaulted structures. In order to survive, their load bearing systems, already subjected to important lateral thrusts, had to withstand additional, rapidly fluctuating vertical and horizontal loads.9 The creation of durable monuments in these adverse circumstances must have been an important challenge for architects and builders alike. Nearly all the remains of the early Byzantine vaulted churches of west Asia Minor have been published and surveyed.10 Still, only the ones of Ephesos and Priene seem to have been the object of detailed excavation reports. Reports on individual monuments often include valuable information about the remains and their chronology, but rarely provide us with convincing reconstructions of the original forms and detailed analyses of the construction techniques. Further information about this bibliography can be found in the following paragraphs, which aim to establish the state of the research for each monument. Before that, however, I would like to emphasize the importance of two attempts to present some of these monuments into a broad perspective.

On the other hand, this same geographical area presented an important disadvantage: it was exposed to very intense earthquakes.7 These seem to have seriously affected cities like Ephesos, Sardis, Philadelphia, and Hierapolis throughout late Antiquity.8 Intense seismic activity must 4

See K. Belke (2008, p. 298). For the role of Ephesos as one of the major early Byzantine ports “standing at the end of the highways into the interior and across Asia Minor”, see C. Foss (2002, p. 130), P. Pensabene et al. (1977, p. 134), and F. Filson (1945, p. 74). The position of Sardis was also privileged for reasons explained in C. Foss (1976, p. 1), and continued being so until the 17th century according to the account of Th. Smith (1678, pp. 235–239). For the links between Hierapolis and the coastal cities along the Aegean shores during this period, see P. Verzone (1956, p. 37) and R. Krautheimer (1965, p. 121). 6 Indeed, according to J. B. Ward-Perkins (1981, p. 273) “Asia Minor is a land of fine building stones and marbles, and in Roman times it was still, for the most part a land of plentiful timber”. The minerals (stone, marble, clay) supplied to Ephesos by its surrounding region have been investigated by D. P. Crouch, (2004, pp. 226–258). 7 Indeed, according to E. Altunel (2000, p. 299) “the fault of the rivers Gediz (Hermos), (…) and the one of the river Menderes (Maeander), with an east-west orientation, constitute the most active structure of western Turkey.” 8 For the effect of late Antique earthquakes (particularly the ones of 358 and 467/8 A.D.) on Ephesos, see C. Foss (1979, p. 190). Seismic 5

activity in the region of Sardis and Philadelphia kept the houses of these cities in a permanent state of decay in the 1st century BC, according to Strabo (1994, 13, p. 181). In 17 A.D., a particularly strong earthquake had devastated twelve cities in the region. According to Tacitus, Annals, II, XXIIIn, the extent of the destruction, obliged the Imperial administration to support the region economically and to engage in a large-scale program of urban regeneration. E. Altunel (2000, p. 301) mentions that Hierapolis and many other cities of the province of Phrygia were destroyed during the earthquake that shook the region in 494 A.D. 9 For the nature of earthquakes and their structural effects, see R. Mainstone (1988, p. 166). 10 Building D at Sardis still awaits its publication.

3

Early Byzantine Vaulted Construction in the Western Coastal Plains and River Valleys of Asia Minor

3. Ephesos, St. Mary, view of the east apse. Construction systems of our region are included in the survey of Byzantine construction methods by A. Choisy (1883). The French author’s tendency to look at the structures through the lens of a builder, combined with the captivating axonometric drawings that bring ruined structures to life makes his book an ideal basis for the exploration of early Byzantine building techniques. Its frequent references to church construction in west Asia Minor illuminate a field that has been somewhat neglected in more recent publications on Byzantine construction techniques.11 Choisy was the first author to examine the churches of Philadelphia and Sardis as examples of a local building practice and to investigate their role in the development of Byzantine architectural forms. A century later, H. Buchwald (1984) resumed this discussion, emphasizing the typological similarities between St. John at Ephesos, Building D at Sardis, and St. John at Philadelphia and the basilicas of Hierapolis, which he considers as examples of the same architectural development.12

The following paragraphs give a sketchy outline of the monuments and an overview of their main publications. Even when their references to structural systems are limited, these surveys are valuable for their descriptions of the visible remains, and for their dating hypotheses. My research is indebted to all these works for unveiling the most enigmatic aspects of these churches, and for guiding my first steps in archaeological sites often chaotic and inaccessible. Saint Mary at Ephesos Today, it is possible to visit Ephesos without even noticing the existence of St Mary. The situation in the early Byzantine times was quite different though, with the church opening its south elevation onto one of the main squares of the city’s ancient harbour, which for centuries had been the gateway not only to Ephesos but also to Asia Minor itself. The scattered ruins that the traveller sees today are not the remains of one church but a palimpsest of different construction phases, the result of destruction related to warfare for some researchers,13 the result of a constantly changing and almost always unfinished building program according to others.

11 Indeed, R. Mainstone (1988) and J. B. Ward-Perkins (1958) concentrate on the investigation of building techniques in Constantinopolitan monuments, while R. Ousterhout (1999) tends to focus on Middle-Byzantine structures. 12 See H. Buchwald (1984, pp. 199–234).

13

The first Austrian excavations published by Knoll (1932, p. 47), revealed that parts of the structure were repeatedly destroyed by fire.

4

Introduction

4. Ephesos, St. Mary, cross-domed church, view of the northeast pier. Entering the site from the east, one encounters an enormous apse, which is flanked by the ashlar masonry walls of two side chambers. Reaching a height of 5.00m, the remains of this apse are faced with small dressed stone blocks (fig. 3). Apse and side chambers seem to form the termination of a short, aisled, basilican structure with two rows of ashlar masonry pillars and a narthex in its west extremity. On the west of this basilica extend the remains of four massive, composite piers with a brick facing (fig. 4). The east piers, surviving to a height of 5.50m, envelop a long chancel with an apse, and incorporate in their structure two chambers with their vaulting almost intact. The spacing and shape of these brick piers is suggestive of the layout of a cross domed basilica. Continuous ashlar masonry walls seem to have formed the lateral boundaries of both the east basilica and the domed church. In the domed church, a series of stone pilasters are found along these walls, without aligning with any of the inner elements of the domed church.

the centre, and a columnar basilica at its east extremity, this seems to be one of the most complex archaeological sites in west Asia Minor (fig. 6). The remains of St. Mary were revealed during the excavations carried out by J. Keil and F. Knoll who published a detailed excavation report in 1932. This report unfolded the story of the monument, classifying its remains in four independent phases, as shown in figure 6. F. Fasolo (1956), basing his study on the constructional analysis of the various surviving walls and supports, suggested that this church may have largely been the result of a single, slow and constantly changing construction process. He was also the first author to suspect that the two parts of the church proper, a domed church and a pillared basilica, coexisted at some point, forming a composite building. The continuation between these two major phases was confirmed to a certain extent by the results of the re-excavation published by S. Karwiese (1989 and 1999). The latter’s careful observation of the foundations identified intermediate, secondary construction stages between the main phases.

Passing through two narthexes, we enter the remains of an atrium surrounded by three colonnaded porticos. The remains of a baptistery, which include the lower portions of four pairs of piers connected by semi-circular niches, adjoin the north flank of this atrium (fig. 5). With a centralized baptistery in its northwest corner, a colonnaded atrium to the west, a cross-domed basilica at

The recent excavations under the direction of S. Karwiese produced new evidence for dating the various phases of the church, revising previous theories. In order to understand the effect of his publications, we need to

5

Early Byzantine Vaulted Construction in the Western Coastal Plains and River Valleys of Asia Minor

5. Ephesos, Baptistery of St. Mary, overall view with the atrium of the church in the background. examine the preceding attempts to date the two main phases, the columnar basilica and the domed church. F. Knoll (1932), and M. Parvis (1945) considered the columnar church as the venue of the Ecumenical council of 431 A.D.14 R. Krautheimer (1965), and P. Verzone (1965), dated the construction of this early basilica to the early 5th century on the basis of the style of the mosaics found in its narthex. F. W. Deichmann (1974), on the other hand, raised the possibility of an early 4th century chronology.15 The recent coin finds of S. Karwiese (1999), however, indicate a later chronology for the columnar basilica, not before the end of the 5th century.16

According to Karwiese, the Ecumenical Council was not held in this basilica, but in the building that preceded it, a late Roman basilica remodeled for the occasion.17 No documentary evidence for the exact dating of the domed church has been found. It is not certain whether it was built before or after the Persian and Arab invasions of the 7th century. P. Verzone (1965), and C. Foss (1979), interpreted this phase as an indication of the reconstruction of the monuments of Ephesos in the 8th century.18 M. F. Castelfranchi (1999) opposed this theory, claiming that the building of a monumental, vaulted church could not have taken place during a period of

14 This proposal was based on an inscription found on site, revealing the dedication of the church to the Virgin, whose nature was the main theme of the Council. See F. Knoll (1932, p. 27), and M. Parvis (1945, p. 72). 15 See R. Krautheimer (1965, p. 80), P. Verzone (1965, p. 608), and F. W. Deichmann (1974, p. 551). The 4th century dating overlooks the account of Bishop Palladios, XIII, 148–168, suggesting that the columns of the basilica were waiting to be incorporated into the structure at least until 400 A.D. 16 This attribution calls for a new reading of the two most important inscriptions found in St. Mary. The first one, found in the narthex, quotes the 6th century bishop Hypatius, and the one in the architrave of the central doorway is dedicated to “Bishop John”. S. Karwiese’s dating of the monument makes the attribution by Restle (1968, p. 164f) of this inscription to John of Ephesos, more likely than the one to St. John the Chrysostom, (M. F. Castelfranchi, 1999, p. 93) or to the bishop who was

installed by the Council of Chalcedon in 451 A.D. (C. Foss, 1979, p. 52). 17 F. Knoll (1932, p. 16) identified the late Roman building that preceded the church as “the Mouseion”, a school of arts and learning. C. Foss (1979, p. 52), inspired by the location of the building, interpreted the same building as the market basilica. However, according to S. Karwiese (1999, p.81), this late Roman basilica was none other than the south stoa of the 2nd century Hadrianic Olympieion of Ephesos, which is mentioned by Pausanias. 18 See C. Foss (1979, p. 112) and P. Verzone (1965, p. 611). Their theory was confirmed by the similarity of the domed St. Mary to St. Sophia at Thessaloniki, a church which was dated to the 8th century by C. Mango (1978, p. 89). Still, the proposal of an earlier, 7th century dating by K. Theocharidou (1992, p. 83), seems to indicate an earlier dating for the domed St. Mary as well.

6

Introduction

6. Ephesos, St. Mary, general layout plan showing the main building phases as identified by F. Knoll (drawing by Karolina Vasilikou, 2009).

7

Early Byzantine Vaulted Construction in the Western Coastal Plains and River Valleys of Asia Minor unrest.19 I am uncertain as to whether the find of early Byzantine pottery shards by S. Karwiese (1989 and 1994), is as sufficient to prove this 6th century dating as the author claims.20 An attempt by the Ephesians to harmonize themselves with the architectural developments of mid-6th century Constantinople, or the last, but vain effort to resuscitate the lost glory of the town after the 7th century?21 Until further proof is forthcoming it might be best to withhold judgment on this question. Still, the possibility that this church was built at the end of the early Byzantine period justifies the examination of its structural form in the context of the present study.

Byzantine vaulted churches. A series of written sources reveal the role of the building. Procopius refers to the contribution of Justinian to the rebuilding and remodelling of this church.25 This contemporary record, and the existence of Theodora’s and Justinian’s monograms in some of the capitals have led scholars to interpret the remains of the church as an example of the ambitious building programmes of the 6th century.26 The numerous subsequent references to St. John reflect its religious role, associated with the tomb of St John the Theologian at its centre.27 This role made St. John one of the most important pilgrimage sites throughout the Middle Ages,28 when the church lay in the centre of medieval Ephesos.29

In two cases, the identification of the phases of St. Mary was accompanied by comprehensive reconstruction drawings. The first graphic reconstruction by F. Knoll (1932) represented the domed church as an independent development that succeeded the destruction of the columnar basilica, retaining only its atrium and baptistery.22 Both phases of the church were reconstructed without galleries, and with a very low roof. F. Fasolo (1956), on the other hand, visualized the early 7th century church as a hybrid building including both the domed basilica, represented with galleries, and the east portion of the early columnar basilica.23 Unfortunately, none of these reconstructions were accompanied by adequate evidence. Also, they tended to focus on the major vaults, neglecting the visualization of secondary vaults whose remains give a rare opportunity to explore early Byzantine vaulting.

The remains of St. John preserve the main lines and structures of an enormous, aisled cruciform church, with an elongated west cross arm (fig. 7). Aisles and nave are separated by the remains of ashlar masonry piers, inserted between groups of marble columns. The piers, made mainly of reused stone blocks, and arranged in a pattern that forms six bays, survive to a height that reaches 5.00m (fig. 8). The northwest colonnade, projecting above the piers, has been restored to indicate the form of the arcades and the existence of galleries. In the crossing, a bema surrounded by a ‘U-Shape’ colonnade, a restored synthronon, and the four columns of a ciborium mark the location of an underground crypt (fig. 9). From this bema started a long platform which led to an ambo located at the centre of the west cross arm. Absorbed by the sight of the massive piers, and the opulence of the marble colonnades, we can overlook the modest, low remains of the outer brick wall and the long buttresses that abut it externally. In the west end, similar walls form a narthex whose space is divided in three parts: a three-bayed central space corresponds to the nave, whereas two lateral single bays give access to the aisles.

My new survey of the remains, found in chapter 6, provides evidence for the new reconstruction of these secondary vaults.24 This chapter also includes a new reconstruction of the vaults of the baptistery and the cross-domed church. These reconstructions are largely based on a new interpretation of the remains, comparisons with churches of a similar type, and new evidence for the existence of galleries.

Exiting the narthex, we encounter one of the most enchanting atria in early Byzantine architecture. The structure, wonderfully restored by the Ephesos Museum, rests on a podium whose walls are made of rubble and brick masonry. This podium, defying the slope of the hill and the line of fortifications that bound the site, projects outwards to form a raised belvedere. Three colonnaded porticos enveloped the atrium, and two pavilions

St John at Ephesos The discovery of the church of St John on the hill of Ayasoluk by G. A. Sotiriou in 1921 marked the beginning of several excavations, surveys, and restoration campaigns. The later gradually brought to light the complex fabric of one of the most important early

25

See Procopius, V. i. 4–7. Procopius’ claim that the Justinianic St. John was “similar in all respects” to the church of the Holy Apostles at the Byzantine capital is crucial for the reconstruction of the Constantinopolitan church, which no longer survives. For a reconstruction of the church of the Holy Apostles on the basis of the remains of St. John, supplemented by the interpretation of two poetic descriptions (“ǼțijȡȐıİȚȢ”), see G. A. Sotiriou (1924, p. 210f). 27 Medieval references to the role of St. John as a pilgrimage destination occur in the chronicles of Willibald [8th century – see T. Tobler (1874)], Abbot Daniel [11th century – see C. W. Wilson (1895)], as well as the one of the ruthless Catalan mercenary Muntaner [14th century – see Goodenough (1921)]. 28 See C. Foss (2002, p. 132). 29 The relocation of Ephesos to the fortified hill of Theologos (now Ayasoluk), was probably caused by the Persian and Arab invasions of the 7th and the early 8th century. For the conditions under which this relocation took place see C. Foss (1977, p. 474). 26

19

For a 6th century dating see F. Fasolo (1953, p. 78). See S. Karwiese et al. (1994, pp. 14–15). M. F. Castelfranchi (1999, p. 90) regards the building of St Mary as an attempt to introduce 6th century Constantinopolitan forms to the capital of the province of “Asia”. 22 F. Knoll (1932) published a detailed reconstructed plan of the late Roman basilica. However, he failed to distinguish the intermediate stages of remodeling that marked the passage from the Roman to the Early Byzantine period. 23 See F. Fasolo (1956, p. 12). 24 These proposals were greatly assisted by photographic, written, and graphic documentation of the building’s structure found in the publications of Knoll and Fasolo. Similar attention to construction details has been often omitted in more recent publications (S. Karwiese, 1989). 20 21

8

Introduction

7. Ephesos, St. John the Theologian, plan of Justinian’s church at ground level, showing main phases (drawing by Karolina Vasilikou, 2009).

9

Early Byzantine Vaulted Construction in the Western Coastal Plains and River Valleys of Asia Minor

8. Ephesos, St. John, general view of the remains from the chancel.

9. Ephesos, St. John, central Bema and restored Synthronon.

10

Introduction

10. St. John at Ephesos, Baptistery, remains of internal nucleus with the restored colonnade of the church in the background.

11. St. John at Ephesos, Skeuophylakion, detail of the central piers

occupied its west corners. The southwest pavilion faces the Temple of Artemis lying at its foot, and the northwest one overlooks the 14th century Seljuk mosque of Isa Bey, with the Kaystros valley in the background.

mausoleum, and a cruciform aisled basilica.30 Further excavations by the Ephesos Museum revealed the baptistery and the skeuophylakion. Their results were brilliantly summarized and interpreted by M. BüyükkolancÕ (2000), and A. Thiel (2005), who also contributed with new reconstruction and dating theories, the first ones to be based on the analysis of the remains.

The remains of a baptistery adjoin the north flank of the west cross arm. Curiously, none of the openings of this building seem to align with the openings of the neighbouring church. The south entrance of the baptistery leads to an octagonal ambulatory, which is inscribed within a square outer wall. The central structure consists of eight piers liked by internal semi-circular niches. A series of octagonal pedestals suggest that eight columns marked the angles of the central octagonal space (fig. 10).

The distinction of phases within the visible remains, and their dating has evolved considerably since the publication of Sotiriou (1924). The latter raised the possibility of a late 6th century dating for the completion of the monument, relying on an inscription found in the narthex.31 Although H. Hörmann (1951) made considerable efforts to study the early phases of the monument on the basis of a few foundation traces,32 he interpreted all the visible remains as the result of a single building phase.33 H. Plommer (1962) was the first author to fully grasp the significance of the constructional and morphological changes between the east and the west parts of the building. His observations led to the attribution of the vaulted transept and chancel to a phase that precedes the time of Justinian and Theodora (527 – 548 A.D.).34 In Plommer’s publication, the famous Imperial pair is only credited with the construction of the west cross-arm. This sound theory was embraced by M. BüyükkolancÕ (2000), who went on, without sufficient evidence, to date the first phase of the vaulted church to the time of Justin I (518–527).35

The remains of the small building identified as a skeuophylakion are found north of the transept of the church (fig. 11). Even though these remains seem to be very modest compared with the ones of the baptistery, their plan reveals an interesting design method of inscribing a circular hall in a rectangular boundary. Whereas the inner faces of the eight piers of the central structure seem to have followed the curvature of the internal circle, their outer faces are straight, and form together with the outer walls four triangular chambers establishing a transition from the central octagon to the external square boundary. The first excavation of the church of St. John was carried out under the direction of G. A. Sotiriou. Until 1922, when the excavation was suddenly interrupted under duress, it had already produced enough finds to allow Sotiriou to trace the plan of the eastern part of the building. This plan, which formed the basis of some interesting typological observations, was included in a study published 1924. The Austrian Archaeological Institute resumed the excavations, which were published by H. Hörmann (1951). The new campaign revealed not only the entire church and its atrium, but also the foundations of two pre-Justinianic phases: a centralized

30

It is largely through Hörmann’s graphic reconstructions that the monument came to be known to the wider public. See, for instance, their use in R. Krautheimer (1986, pp. 243–244). 31 See G. A. Sotiriou (1924, p. 167). 32 For an attribution of the first cruciform church to the mid-4th century, see H. Hörmann (1951, p. 205). 33 H. Hörmann (1951, p. 100) admitted the existence of only a brief pause between the construction of the transept and the building of the nave. 34 See H. Plommer (1962, p. 124). 35 See M. Büyükkolanci (2000, p. 68).

11

Early Byzantine Vaulted Construction in the Western Coastal Plains and River Valleys of Asia Minor

12. Sardis, Building D, view of southwest pier from the southeast.

12

Introduction reconstruction, whose richness competes with Hörmann’s, has a totally different character from the one published half a century ago. Pendentive domes over the cross arms surround a hemispherical dome that makes the crossing the indisputable climax of the composition. Two other important new features are the fenestrated base of the central dome as well as the large clerestory windows in the lunettes of each bay of the nave. A. Thiel failed to provide sufficient archaeological evidence for his reconstruction choices, which are explained on a more stylistic basis.

Recently, A. Thiel (2005) suggested an alternative phase sequence, which identifies the walls surrounding transept and chancel as the results of an early phase dated to the early 6th century. The inner piers were attributed to a continuous construction phase that, according to Thiel, started around 540 A.D. and was completed in the late 6th century.36 Thiel’s interpretation of the remains does not explain the serious differences between the east and west piers and colonnades. In our study, we will rely mostly on Plommer’s and BüyükkolancÕ’s interpretations, taking also into account Thiel’s observation that the east outer walls were probably built before the east piers. Synthesizing these studies, we can attribute the early Byzantine remains of the church to three main phases, as shown in figure 7.37

This lack of adequate substantiation is all the more frustrating as there are still four major vault fragments on the site, which, correctly interpreted, can not only provide proof for reconstruction, but also reveal some of the vaulting methods followed in the monument. A complete survey of these fragments can be found in Chapter 3. This survey leads to a new documentation of vaulting methods as well as to a new, illustrated reconstruction of the vaults of St. John (see fig. 114).

In reconstructing the building for the first time, Hörmann (1951) was confronted with a very difficult task. This required him to draw information from relatively limited remains, and enigmatic historical descriptions, open to various interpretations. One of the characteristic aspects of his reconstruction is the richness of its graphic presentation. Apart from the customary plans, sections and elevations, the latter also includes a series of wellexecuted perspective drawings, reminiscent of the ones of the Cité Industrielle, by Tony Garnier. Hörmann visualized the building with six major domes on pendentives, four hemispherical ones over the transept and chancel, and two semi-ellipsoidal ones over the rectangular bays of the west cross arm.38 Based on the 14th century description by Ibn Battuta,39 who had counted eleven domes, Hörmann added five small domes over the bays of the west gallery.40 The most striking feature of the perspectives published in 1951 is a series of massive flying buttresses abutting a continuous dome base.

Building D at Sardis The six colossal dilapidated piers that constitute the remains of Building D are likely to be some of the most important vestiges of the early ecclesiastical architecture of Sardis (fig. 12). At first sight, these unexcavated remains do not seem to preserve any features typical of a church. Still, both the scale and construction details of the monument seem to be typical of early Byzantine, vaulted church architecture in the region. The characteristic early Byzantine features in the construction of Building D are the combination of ashlar, brick and rubble masonry, the systematic use of spolia from Roman buildings, and the thick mortar joints in the brickwork. The imposing scale of the remains may also be considered typical of monumental building that precedes the 7th century. We realize that, even though there is no sufficient evidence for dating the monument, a series of indications lead us to surmise that its remains belonged to an early Byzantine church.

Hörmann’s reconstruction was criticized on stylistic, aesthetic and structural criteria. The alternative proposal published by H. Plommer (1962) represents the buttresses with sloping tops and alters the proportions of the interior. Later reconstructions by Ch. Strube (1973) and F. Hueber (1997), questioned the substance of both the flying buttresses and the small domes over the west gallery, and raised the possibility that the central dome was more prominent than the domes over the cross arms.

The six piers delimit a rectangular space, comprising two oblong bays. Their plan has a re-entrant angle profile and general dimensions which range from 4.00x5.20m to 5.50x5.20m (fig. 13). A careful examination of the remains indicates that the nave, which measures approximately 32.00x16.00m, was not longer than it is today. Indeed, the profile of the west piers, clearly suggesting that they stood on a corner, excludes the possibility that the building extended further west. Also, the fact that the upper east side of the southeast pier preserves traces of an external wall facing suggests that this pier marked the southeast extremity of the building (fig. 14).41 The existence of individual blocks that seem

These efforts seem to have influenced the recent publication by A. Thiel (2005). His graphic 36

See A. Thiel (2005, pp. 100–103). I have followed many authors in attributing the baptistery to the preJustinianic church. Most attributions have been based on an inscription which, like the one in St. Mary, refers to a certain “Bishop John”. The inscription led C. Foss (1979) to suggest a 6th century dating, which seems improbable, given the misalignments and constructional differences with the main church. The attribution to the 5th century, supported by M. Büyükkolanci (1982 and 2000), and M. F. Castelfranchi (1999) seems more likely. 38 The galleries, reconstructed on the basis of column and pier fragments, are shown to have the same intercolumniations and to be covered by the same barrel vaults as the aisles below them. 39 See M. Büyükkolanci (2000, p. 39), as well as my interpretation of this description in Chapter 3, Section 2. 40 See H. Hörmann (1951, p. 160). 37

41

Choisy (1883, p. 140), was the first to publish a reconstructed plan of the church, which he calls “St John”. However, there is no evidence for the existence of an apse or the dedication to St John. Still, Lampakis, who visited the church in 1906, mentioned that the Greek locals considered these ruins as the remains of the church of St John.

13

Early Byzantine Vaulted Construction in the Western Coastal Plains and River Valleys of Asia Minor

13. Sardis, Building D, reconstructed plan (drawing by Karolina Vasilikou, 2009). to project out of the main mass of the piers is probably indicative of the existence of lunette walls or screens between them. The facings of the piers are made of reused limestone and marble ashlar blocks. These facings enclose cores of mortared rubble mixed with reused fragments of architectural elements such as architraves, cornices, column drums, and capitals. Spolia are concealed without consideration for their interesting sculptural ornamentation. C. Foss (1977) and M. F. Castelfranchi (1999) have attributed the building to the times of Justinian and identified it as the Cathedral of Sardis.42 Still, there is no proof in support of such a dating. More evidence for dating is likely to be found in a future excavation. For the time being, we rely on the reasonable hypothesis that the building must have been built before the Persian devastation of the city in 616 A.D.43 Although the visible remains do not provide enough evidence for dating, they offer numerous clues for the original form of the monument. Several of these clues have been evaluated by A. Choisy (1883), whose reconstruction includes a brief description, a plan and a cut-away axonometric of one of the pendentives. The plan shows an apse on the east side of the building. 42 43

14. Sardis, Building D, view of southeast pier, showing detail of external wall facing.

See M. F. Castelfranchi (1999, p. 97) and C. Foss (1976, p. 99). See C. Foss (1975, p. 738).

14

Introduction

15. Philadelphia, church of St. John, view of northeast pier from the southwest.

15

Early Byzantine Vaulted Construction in the Western Coastal Plains and River Valleys of Asia Minor

16. Philadelphia, St. John, reconstructed plan (drawing by Karolina Vasilikou, 2009).

The fact that no traces of such a structure survive today either means that the fabric of the monument was more complete at the end of the 19th century or that the apse appearing in Choisy’s plan is hypothetical.44 Earlier depictions, such as the miniature plan in a map by Giovanni Battista Borra (1750), and the view of the ruins in the background of a painting by Thomas Allom (1830), do not include any curved elements resembling an apse.45 They both seem to indicate that the state of the monument has not altered dramatically in the last 250 years.

reconstruction proposal for the vaults of the building, based on new evidence for pendentive domes. St John at Philadelphia Three piers similar to the ones of Sardis dominate a landscaped archaeological site in the center of Alaúehir (fig. 15). Their location probably corresponded to the center of the walled precinct of early Byzantine Philadelphia.46 According to a local tradition, which survived until the late 19th century and was reported by E. Curtius, these piers were considered to be the remains of the church of St. John. Fresco scenes with a religious subject, recorded by G. Lampakis (1906) and H. Buchwald (1981), and now destroyed, indicate that these are indeed the remains of a church. The central location of the remains, their large scale, and the quality of their construction seem to suggest that this was one of the main churches of Philadelphia, perhaps even its Cathedral.47

Indirect evidence for the existence of an apse may be found in the plan of the building itself. The fact that the easternmost piers are thinner than the others may be explained by the earlier existence of an apse between them. The latter would assist in the counteraction of lateral thrusts, reducing the need for the piers in its flanks to be as massive as the other ones. This observation is indicative of the degree to which the study of the plan and the interpretation of vault fragments can provide evidence for reconstruction. This strategy is followed in the 5th chapter of this dissertation, which includes a new

46

We know from J. Lydus, IV, 29, that, in the Hellenistic period, Philadelphia was called “little Athens”, because of its great number of temples. Our observation concerning the possible location of the building in Philadelphia relies on E. Curtius, (1873, p. 94). The latter described remaining parts of the city’s fortifications, located its Stadium, Theatre, and one of its small temples, and gave a sketchy outline of the remains of the church of St. John. 47 See H. Buchwald (1981, pp. 301–302).

44 There is a lack of clarity in A. Choisy (1883, pp. 160–161), concerning this point. The second explanation seems to be the most probable, as the apse in question appears to be drawn with a less intense outline and infill than the surviving piers. 45 See C. H. Greenewalt (2003, pp. 27, 39).

16

Introduction

The three enormous ashlar masonry piers carry huge vault fragments. Piers and vault fragments form giant masses of masonry whose height reaches approximately 14.00m. The re-entrant angle profile of the piers is slightly more complicated than the one found at Sardis: here, the faces are recessed twice. The plan of the east piers leaves no doubt that they stood at the east extremity of the building. The plan of the northwest pier however, as well as the vaults that spring from its top towards the west suggest that the nave of the building extended further west, so as to include at least one more bay, as shown in figure 16. This plan exhibits enormous rectangular niches between the piers. The precise function of these spaces remains uncertain. The fact that the niches occupied half of the total surface of the church’s interior seems to suggest that they had an important functional or liturgical role. The inner faces of the piers are made of ashlar masonry. The lower portion of their north, exterior facing has collapsed, exposing the structure of the core, which consists mainly of mortared rubble. Turning our attention to the vault fragments, we can clearly distinguish arches and pendentives made of bricks springing towards the inside of the church. Vault remains are rarely found so well preserved in west Asia Minor. The north faces of these vault fragments, which seem to have survived the collapse of the wall facing below them, are also interesting: they include fairly large façade traces, displaying features indicative of a rich articulation, which is further explored in Chapter 5 (fig. 17).

17. Philadelphia, St. John, view of northeast pier from the north, showing detail of external facing.

E. Curtius (1873) published the first account of the monument. This was a very brief description that did not do justice to the church’s architectural forms and scale. A. Choisy (1883) attempted to fill some of the lacunae of Curtius’ description by publishing a schematic plan of the monument, accompanied by a remarkably accurate axonometric of the vault fragment on top of the northwest pier.48 These drawings served to illustrate a text including broad definitive statements concerning the alleged role of these buildings in the transition from late Roman to early Christian architecture. Our present knowledge of the church is indebted to the survey published by H. Buchwald (1981). The most valuable part of this publication is its exhaustive analysis of the visible remains. It also includes a schematic reconstruction and an interesting effort to interpret the building as an example of a local tradition of vaulted construction. M. F. Castelfranchi (1999) did not agree with the absence of aisles in H. Buchwald’s reconstruction.49 However, she does not seem to have taken into account the finds of the excavation of the southwest pier, which were published by R. Meriç (1990). The latter revealed the continuous straight wall that once enveloped the piers enclosing the central, aisleless space of the church (fig. 18). 48 49

18. Philadelphia, St. John, view of southwest pier, with the remains of the wall that enveloped the nave visible in the foreground. The main lines and structures of the plan, as reconstructed by H. Buchwald, seem to be a good basis for completing some of the lacunae in our knowledge of the building. It is still uncertain whether the church was covered by pendentive domes or domes on pendentives. Also, the 1981 survey has identified a series of façade fragments whose potential as evidence for reconstruction

See A. Choisy (1883, plate XVI, 1). See M. F. Castelfranchi (1999, p. 96).

17

Early Byzantine Vaulted Construction in the Western Coastal Plains and River Valleys of Asia Minor

19. Hierapolis, Urban Basilica, view of the nave looking east. of the elevations has not yet been fully evaluated. Finally, it seems that further study of the structural fabric is required, in particular in areas such as the core of the vaults, or the form of their shell. My survey of the monument has attempted to resolve these issues. Its main results, a new reconstruction of vaults, based on new evidence for domes on pendentives, and a representation of the original elevations, can be found in chapter 5.

the churches of Ephesos, three of these basilicas have resulted from the drastic remodelling of earlier late antique structures. They can be seen as characteristic examples of retrofit during the early Byzantine period. Even though walls and supports are relatively well preserved, the almost total absence of vault fragments diminishes the role of these churches in our investigation of vaulted construction. Still, they constitute good sources of information about the materials and construction methods employed in load bearing elements. This justifies the frequent reference to them in the first two chapters of this book.

The Vaulted Basilicas of Hierapolis, Priene and Pythagorion In the vicinity of the west and east extremities of our region we find the remains of four pillared basilicas with similar characteristics. The two large basilicas of Hierapolis, as well as the smaller basilicas of Priene and Pythagorion are aisled and have a nave that is divided in three major bays. Even though the remains themselves do not preserve any trace of vaulting, the scale of the piers and their layout suggest that these churches were vaulted. The dependence of their spatial organization on a series of modular units seems to inscribe them in the same architectural development as St. John at Ephesos, Building D at Sardis, and St. John at Philadelphia.50 Like 50

The church of the Thermae and the “Urban Basilica” of Hierapolis are two of the most interesting and iconic monuments of Asia Minor. Located at the centre of the Early Byzantine Hierapolis, and facing its cardo, the “Urban Basilica” must have occupied one of the city’s most prominent locations (fig. 19).51 Verzone (1965), to whom we owe a detailed study of the church,52 published an inscription that mentions the church in conjunction 51

P. Verzone (1956, p. 52) has raised the possibility that this was the city’s early Byzantine cathedral. 52 Brief references to the church occur in the books Hierapolis di Frigia 1957–1987, (1987), pp. 120–130, as well as Saggi in Onore di Paolo Verzone, a cura di Daria de Bernardi Ferrero: Hierapolis Scavi e Ricerche IV, (2002).

This development has been explored by H. Buchwald (1984, p. 210).

18

Introduction

20. Hierapolis, Urban Basilica, reconstructed plan (drawing by Karolina Vasilikou, 2009). with one Kyriakos, who lived at the times of bishop Gennadios (after 535 AD). This find encourages the dating of the building to the time of Justinian, when Hierapolis assumed the role of the capital of Phrygia.53

evidence for reconstruction is forthcoming, it would be better to withhold judgement on this subject. The church of the Thermae, located in the west outskirts of the city, preserves most of its piers and arches up to a considerable height, and may be considered one of the most impressive monuments of the region (fig. 21). The two most recent studies dedicated to this church are the ones of P. Verzone (1956) and M. L. de Bernardi (2002). P. Verzone’s publication was the first to determine the two main phases of the building, identifying the outer parts of the piers and their arches as the remnants of the central hall of a late Roman Bath complex. According to him, the transformation of this hall during the early Byzantine period included the extension of the main piers of the church towards the interior and the addition of an apse (fig. 22).54 It is likely that this change also involved the replacement of the original vaults by new ones with a smaller span. Verzone surmised that the nave of the church was covered by three domes on pendentives.55 The remodelling of the building introduced two new elements in its spatial organization. A new system of

Visiting the remains of the church, we immediately distinguish six major ashlar masonry piers dividing the nave into three square bays, adjoined by a spacious, rectangular chancel. In the aisles, the inward stance of pilasters, and a series of columns placed next to the outer wall transform what could easily have been a single, corridorial space into a rhythmically articulated, interesting yet axial design (fig. 20). The east extremity of the church consists of an apse flanked by side chambers. The compartmentalization of the internal space and the presence of massive piers led P. Verzone to visualize the church with a sequence of spherical vaults. The Italian author failed to evaluate an alternative reconstruction, which seems to be more attuned to the specific form of the main piers. The form of these piers betrays a height difference between longitudinal and transverse arches, which is hardly compatible with spherical vaults. A reconstruction of the nave with a barrel vault resting on reinforcing arches that divide the nave into bays seems more probable. Still, until further

53

54

According to P. Verzone (1965, p. 624), another aspect of this remodelling was the dramatic reduction of the light of the interior, caused by the blocking of the wide windows of the thermal bath building. 55 See P. Verzone (1956, p. 40) and (1965, p. 622). For a similar reconstruction, see H. Buchwald (1998, p. 211).

See D. De Bernardi Ferrero (1983, p. 91).

19

Early Byzantine Vaulted Construction in the Western Coastal Plains and River Valleys of Asia Minor

21. Hierapolis, extramural “Church of the Thermae”. The late Roman piers and stone voussoir arches can be seen in the foreground. The lower projection from the central pier is an addition, made when the structure was converted to a church.

oblong bays was created and aisles were introduced. These new elements must have played a major role in giving the building the characteristics of a church.56 An external appearance dominated by the systematic use of ashlar blocks of honey-coloured limestone distinguishes the two churches of Hierapolis from the other monuments of the region. Perhaps, this peculiarity is there to remind us that entering Phrygia, we move away from the influence of brick construction methods typical of Constantinople and west Asia Minor. The plan of the “Urban Basilica” of Hierapolis has many points in common with the one of the basilica of Priene. This basilica, located just south of the theatre of Priene, seems to defy with its position and orientation the Cartesian layout of the city. It not only blocks the street in front of the theatre, but it is also tilted in relation to the urban grid. Its remains, relatively well preserved, lack the

22. Hierapolis, “Church of the Thermae”, schematic plan showing the early Byzantine additions (hatched) to the late Roman structure, during its conversion to a church (sketch by Nikolaos Karydis, 2004).

56

M. L. De Bernardi (2002) repeats several of P. Verzone’s observations. Still, this publication includes an exhaustive overview of the 18th and 19th references to the monument, including the ones by Tremaux (1858), and A. Choisy (1875).

20

Introduction

23. Priene, Early Byzantine Basilica south of the Theatre. View of the nave looking west. integrity of the surrounding, earlier buildings. Observing these remains, we can easily distinguish two different structural frameworks. First, there are two colonnades consisting of reused Doric columns 3.00m high, and a lower surrounding wall made of roughly dressed stones (fig. 23). Secondly, there are eight piers with a rubble masonry facing, which are inserted between the columns, dividing both the colonnades and the space between them into three parts (fig. 24). The combination of these two frameworks, in addition to an apse on the east and a narthex on the west, create a spatial layout characteristic of an aisled basilica with three bays. The recent article by S. Westphalen (2000) includes a detailed description of the remains, and attributes them to three building phases. The surrounding walls and the columns were identified as parts of an earlier, aisled basilica with a narthex. The second phase involved the narrowing of the narthex, while the third one added the piers. As Westphalen observed, this last phase must have altered dramatically the character of the church by introducing a vaulted roof. In the absence of vault fragments, however, the nature of the vaults of the building remains uncertain.

24. Priene, Early Byzantine Basilica, nave pier and detail of pedestal. A very similar basilica to the one of Priene was excavated in 1979 at Pythagorion, on the Greek island of Samos, a site less than a mile away from Asia Minor’s coast. Shortly after the excavation, K. Tsakos (1979) published a short report on the building, which includes a minute description of its remains, a speculative dating to the 21

Early Byzantine Vaulted Construction in the Western Coastal Plains and River Valleys of Asia Minor

25. Pythagorion, Samos, “Tria Dontia” Basilica, reconstructed plan showing the main phases as identified by the author (drawing by Nikolaos Karydis, 2008).

22

Introduction

26. Pythagorion, “Tria Dontia” Basilica, view of the three major buttresses.

27. Pythagorion “Tria Dontia” Basilica, panoramic view of the internal colonnades.

6th century, as well as the identification of two main building phases. Until now, however, no plan has been published, making the interpretation and reconstruction of the church practically impossible. In my survey of the building in July 2008, I attempted to repair this lacuna, measuring the remains and tracing the plan of the building (fig. 25).

He also suggested that short barrel vaults extended sideways oversailing the aisles. This theory seems to be confirmed, if not entirely proved, by the close observation of our newly prepared plan. The present work constitutes the first survey entirely devoted to the construction techniques employed in the above churches. Although previous publications often included important observations on the structure of individual churches, there has never been an attempt to synthesize these observations, and to see these monuments as products of one multifaceted pattern of building. Also, construction analyses included in them are often incomplete. Most of the publications often fail to focus on construction details that are vital for the graphic visualization of the original structures, and tend to present reconstruction drawings that rarely give any clues about the original structural fabrics.

The site of the monument is known today as Tria Dontia (i.e. “three teeth”) because of the massive ashlar masonry buttresses that dominate the scenery (fig. 26). These buttresses are connected by a massive wall more than 3.00m thick, with an ashlar masonry facing and a mortared rubble infill. The remains of this wall, together with the ones of a north wall, surround a rectangular space that measures 14.50x23.00m. On the east of this space there is an apse with a polygonal outline, and on the west we can roughly distinguish the foundations of a narthex. According to K. Tsakos (1979), these remains belonged to an aisled, timber-roof basilica. A later stage brought the introduction of rectangular piers, the enlargement of the surrounding wall in four parts, and the division of each of the earlier colonnades into three pairs of columns (fig. 27). As no part from the upper portion and the vaults of the building survives, it is difficult to make any suggestions about its original form. Still, Tsakos visualized the remodelled basilica with a dome over the central bay and with barrel vaults over the other two bays.

2. Methodology The present study has two main aspects: the survey of structural systems, and their reconstruction. The survey of the monuments has a double purpose: to investigate their materials and building techniques, but also to identify construction details and fragments with a potential

23

Early Byzantine Vaulted Construction in the Western Coastal Plains and River Valleys of Asia Minor contribution to the visualization of the original structures. The fragments of each church, drawn in scale, analysed and interpreted on the basis of comparisons with other monuments, can be vital for the reconstruction of missing elements such as vaults. Reconstructions like the ones proposed for individual monuments from chapter 3 onwards are the most important part of the present research. Not only do they create a window into complex vaulted forms, but they also facilitate the observation of vaulting techniques and their typological classification. Even though my survey of materials in chapter 1 does not contain new information about early Byzantine vaulted construction, it is essential for the general understanding of building techniques employed in the region. My intention in this chapter is to document the appearances of the major materials used, dressed stone, rubble, brick, and mortar, in the hope to establish the building logic that guided their use in particular parts of the structures. I also examine the nature and origins of materials, as well as their distribution in the region. The wide variety of materials found in the remains reflects the complexity of load bearing structures in west Asia Minor, the investigation of which is the main object of chapter 2. The latter focuses on the main types of masonry structures used: ashlar, rubble and brick masonry. The same chapter concludes with a survey of colonnades, in an attempt to study the methods used to integrate slender, brittle and monolithic supports in heavy structures susceptible to considerable deformation. My reconstruction methodology starts from the analytical evaluation of an extensive body of new drawings documenting the structural fabric of these churches. In chapters 3–6, I concentrate on the graphic recording of those specific details, which materially serve the understanding of the churches’ original vaulting patterns. Information about the latter can be drawn from vault fragments that I have newly identified. Their interpretation is based to an important extent on the detailed observation of other early Byzantine vaulted churches found in the Aegean coastlands and Constantinople. The results are a series of new or revised graphic reconstructions of the monuments, which, in most cases, represent both the form of the vaults, and their structure. The new insights into the structure of vaults form the basis of their new typological classification. The new vault typology, found in chapter 7, gives me the opportunity to observe the way in which different vault structures and forms were used, as well as the principles that guided their choice.

24

Part 1 The Surviving Structure: Materials and Techniques

ruined churches like these an ideal field for exploring early Byzantine materials and construction methods.

With the architectural form of west Asia Minor’s vaulted churches barely recognizable today, with the main historical literary sources describing them accurately – if any – possibly lost forever, the luckless researcher is faced with enigmatic piles of stone blocks, bricks, and mortared rubble, which, at first, do not seem to conserve much of the architectural and structural principles employed in these Early Byzantine churches. However, a closer look at this scattered material, a look that forgets speculation concerning architectural forms in order to focus on the characteristics and qualities of the units that compose the ruins is likely to offer a better insight into Early Byzantine Architecture than originally thought.

One of the main characteristics of early Byzantine vaulted construction in west Asia Minor is the synthesis of a wide variety of construction materials. Most of the surviving structures look like amalgams of brick, mortar, rubble, and dressed stone. The following chapter will try to establish the criteria and building logic that guided the use of these materials. Chapter 2 will focus on the techniques with which these materials were assembled to form walls and supports. The area of the load bearing components is one of extreme interest. The exploration of this field will attempt to interpret the ways in which elements as different as gigantic masonry piers, marble columns, and masonry walls were combined in complex load bearing systems to provide adequate support for the large, heavy vaults of the churches. The hallmark of vaulted church architecture in the region is not only found in the visual magnificence of the vaults but also in the structures that carried these vaults and counteracted their lateral thrusts. Without the development of adequate load bearing elements, vaults would have never become a standard element of ecclesiastical architecture in this earthquake prone region.

The ruined condition of the monuments makes it difficult to appreciate the splendour of their original internal decoration or their elaborate vault geometry. However, the same ruins give us a rare insight into the building technology employed in these churches. The disclosure of the inner layers of construction and our proximity with architectural elements that lie on the ground offer the opportunity to examine every minor aspect of the structural frame, including its materials and building techniques. Our ability to study structural elements that would originally have been concealed or too distant from the observer makes

25

Chapter 1 Building Materials

1. Fired Brick

28. Ephesos, St. John, chancel. Detail of brick masonry wall.

In the churches of Ephesos, Sardis, and Philadelphia, the remains indicate that there are only a few parts of the original construction where kiln baked bricks had not been used. The choice of this material in the construction of walls, piers, and vaults was by no means a novelty. Fired brick had been a regular feature of Roman Imperial Architecture in the region and, by the 4th century, baths, basilicas and libraries of cities like Pergamon, Ephesos, and Sardis must have already displayed its wide potential and virtues as a building material.57 It is on these precedents that Early Byzantine builders and architects based their own construction techniques.58 These techniques probably contributed to maintain demand for the regular production and supply of bricks. Even in this case, however, the systematic reuse of bricks extracted from ruined monuments must have been an important obstacle in the development of brick industry in west Asia Minor.

29. Ephesos, St. Mary, cross-domed church. View of pier faced with brick masonry.

The Use of Brick in Walls and Supports

External walls made purely of brick and mortar were not very frequent. Remains of such structures can be seen in the remaining walls of St. John at Ephesos (fig. 28). In the external walls of St. Mary bricks were only used above a certain height (about 2.5 m) resting on top of megalithic ashlar masonry.59 The use of the same material in piers seems to have been less extensive than the use of stone. St. John and St. Mary in Ephesos are the only instances where brick has been used either as a facing material, as in St. Mary (fig. 29), or in the entire upper part of the pier, starting from the level of the floor of the gallery. Fired bricks were also used to form reinforcing bands that usually occupied the entire wall thickness alternating with layers of rubble masonry. This use of brick is regularly encountered in west Asia Minor. In Ephesos, brick bands are observed in extensive parts of the external walls of the main church, the skeuophylakion, and the baptistery of St. John

The sheer quantity of bricks in the remains of Ephesos, Sardis, and Philadelphia, and the diversity of ways in which they were introduced in load bearing structures, betray the familiarity of early Byzantine builders with this material. Bricks have been used as the main material in wall construction, in reinforcing bands running through masonry walls, in pier facings, and, rarely, in relieving arches, not to mention the frequent use of brick dust as a pozzolanic additive in mortars. This multiplicity of applications must have made fired brick essential for the construction of churches in west Asia Minor. 57 J. B. Ward-Perkins (1958, pp. 85–86) has suggested that “throughout the pre-Byzantine period, [in west Asia Minor] brick was a secondary building material, used mainly in constructional detail”, and that buildings such as the Serapeum at Pergamon, constructed entirely of brick “were exceptional”. Yet, twelve years later, in the occasion of his monograph on Roman Imperial Architecture, he claimed that the quasiexclusive use of fired brick in the Serapeum “was no mere local eccentricity”, and that this “was regular practice (…) in Roman Asia Minor”. See J. B. Ward-Perkins (1981, p. 277). 58 A similar view concerning the origins of the use of fired brick in Asia Minor is found in H. Dodge (1987, p. 114).

59

For a dating of the walls, which is based on archaeological evidence from sherds and coins, see S. Karwiese (2004, pp. 315–316). A description of the structure of the walls in question occurs in F. Knoll (1932, pp. 27–28).

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Early Byzantine Vaulted Construction in the West Coastal Plains and River Valleys of Asia Minor

30. Ephesos, St. John, chancel. Detail of relieving arch. (see fig. 11), and in the perimeter walls of the baptistery of St. Mary. Similar elements occur in the scanty remains of the lunette walls of St. John at Philadelphia, as well as in the upper portion of the piers of Building D, at Sardis. This material, therefore, seems to be omnipresent in the load bearing structure of churches, and even in components subjected to excessive loads.

The almost total absence of brick remains from the sites of the vaulted basilicas of Priene and Hierapolis raises doubts as to whether brick was the only vaulting material in west Asia Minor. Yet, it must be noted that, at least in the case of the “Urban Basilica” at Hierapolis, some traces of brick structure can be distinguished today in the deep debris that covers the nave (fig. 31).60 This suggests that the rarity of brick in these monuments must be attributed to the dilapidation of their structures over the centuries.61

The Use of Brick in Arches and Vaults Although up until the level of the upper pier and wall cornices, brick is clearly not the sole material used, its use seems to be almost exclusive in vaults and arches. However, in reality, that is not always the case: in Building D at Sardis, and in St. John at Philadelphia, burnt brick has been used only in the shell of the vaults, concealing cores consisting mainly of mortared rubble. In the above cases, the only use of brick in the vault cores is in the form of levelling bands. St. John at Ephesos is the only example where the vault structure consisted entirely of brick courses set in thick courses of mortar. The same church offers numerous examples of brick relieving arches, the remains of which are quite rare in the early Byzantine churches of the area (fig. 30).

The Reuse of Bricks The use of spolia, one of the most characteristic aspects of early Byzantine church construction, has mainly been associated with the reuse of marble and stone members. Still, a close observation of brickwork in the churches of 60

H. Buchwald (1984, p. 210) claims that “remnants of the vaults may still be found in the very deep debris inside the nave.” My discovery confirms this. P. Verzone (1956, p. 56) does not mention these minor brick remains. According to P. Verzone, “delle volte non sono rimasti residui di sorta”. He suggests that the vaults of the “Urban Basilica” were probably built with dressed blocks, according to what seems to have been a general practice at Hierapolis. 61 For the attribution of the disappearance of bricks to the combined action of weather (corrosion) and thieves, see J. B. Ward-Perkins (1981, p. 276).

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Building Materials

31. Hierapolis, “Urban Basilica”. View of the debris inside the nave, showing traces of brick structure. Early Byzantine Brick Making

west Asia Minor indicates that brick must have also been regularly reused.62 Often, we encounter walls or even piers where the sizes and colours of bricks seem to be so varied that it is difficult to believe that the latter had a common source. The broken surface of some bricks could also be considered as an indication of their reuse.63

Little is known about the techniques employed in the production of bricks in early Byzantine Asia Minor. According to R. Ousterhout, brick manufacturing followed a tradition established in this region during the Roman Imperial period.64 Bricks were probably produced locally by small workshops.65 The viability of this activity must have been threatened by the tendency to reuse bricks, even in the building of monumental structures. Still, judging from a series of middle Byzantine documents and from the systematic use of the material in early Byzantine and “Dark Age” church Architecture, large-scale production of fired bricks must have continued throughout the Byzantine period.66

The church at St. John at Ephesos offers the opportunity to study the role of reused bricks in early Byzantine monumental construction. In this church, reused bricks occur in the two internal buttresses flanking the apse – elements probably added during a subsequent consolidation of the original structure (fig. 32). Reused bricks also occur in the apse itself, as well as in the external walls of the nave. Still, in other structural components, such as vaults, bricks are regular and broken pieces rare. This shows that this material was produced for the church. We realize that reused bricks had a relatively small role in the structure, either as the material used in small, later additions, or as odd pieces within brickwork essentially made of new material.

64

In my description of the brick-making process, I rely extensively on passages of the book by R. Ousterhout (1999, p. 129), and his research in Middle Byzantine written sources and illustrations. Byzantine written records on brick making are often indirect and elliptical. In order to draw information from illuminated manuscripts, important interpretative efforts are required. Interpretation of texts and figures can be assisted by the study of historical accounts on pre-industrial brick-making methods such as the ones discussed in J. Ayres, (1998), pp. 102–106. 65 According to H. Dodge (1987, p. 112), “there is little evidence in Asia Minor for a centrally organized brick manufacturing industry.” 66 See R. Ousterhout (1999, pp. 128–132).

62 The practice to reuse bricks is also found in Justinianic Constantinople. R. Mainstone (1988, p. 69), claims that the bricks used in the reconstruction of the western arch of Hagia Sophia “were taken from earlier structures elsewhere and reused”. 63 The criteria I have used to identify reused bricks are the same as in H. Buchwald (1977, p. 270).

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Early Byzantine Vaulted Construction in the West Coastal Plains and River Valleys of Asia Minor

32. Ephesos, St. Mary, cross-domed church. Detail of apse wall with bricks of different colour and size.

33. Sardis, Building D, detail showing bricks that have probably fallen from the vaults. Notice their soft arises and bent surfaces.

The long manufacturing process seems to have involved particularly hard and unhealthy labour.67 A Middle Byzantine illuminated manuscript shows that the process started with the screening of the clay extracted from the quarry (aimed at the removal of oversize particles), and its mixing with water in a pit.68 The next steps were the addition of mineral agents such as sand, or crushed pottery to the mixture, and, after that, the formation of the clay in moulds.69 That this formation was made without excessive care for the regularity of the resulting shape of bricks is attested by the soft arises and bent surfaces typical of early Byzantine bricks in west Asia Minor (fig. 33). The final stage consisted in firing the bricks in a kiln, probably not very different from the two early Byzantine kilns excavated at Hierapolis.70 These kilns, dated to the 6th or the 7th century by the excavators, were located in the urban periphery.71 They were circular internally, with a diameter of 3m, and rectangular externally. Excessively thick walls guaranteed thermal insulation. The space was divided in two levels separated by a perforated terra-cotta frame. The lower level was a hypocaust. In it, a fire of wood or charcoal was lit baking the bricks stacked in the upper chamber.72

Brick Sizes In the walls of St John the Theologian at Ayasoluk the side dimensions of bricks range from 34cm square up to even 38cm square, while their thickness oscillates between 3.5 and 5.5cm. The above irregularity is typical of almost all the monuments under consideration where brick has been used.73 Researchers exploring the development of building techniques in Early Byzantine Constantinople have suggested that from the 4th to the 6th century there has been a consistent tendency for the size of bricks to get from an average of 39 cm sq. down to 34– 36cm sq.74 This observation does not seem to apply to the two vaulted churches at Ephesos. Indeed, in St. John, the bricks used in both recognizable building phases appear to have roughly the same side dimensions and to differ only slightly in thickness. 75 In the church of St. Mary, the bricks used in the east Apse, a structure belonging to the earliest building phase of the church, are even smaller than the ones used in the later, domed church. In St. John at Ephesos and St. John at Philadelphia, there is a distinction between the bricks used in walls and the ones used in wide arches and domes. Thus, bricks used in arches and vaults that either carry significant loads or span wide distances are usually larger than the standard ones, measuring 35x50x5cm and 35x70x4.5cm

67 Indeed, a passage from the Bible (Exodus 1.14), noticed by R. Ousterhout, mentions that the Egyptians “made the lives [of the enslaved Israelites] bitter with hard labour in the clay quarries and in the brickmaking”. J. Ayres (1998) observes that, in pre-industrial England “much of the work involved arduous and basic labour”. 68 The screening of clay and its mixing with water are depicted in a middle Byzantine illuminated manuscript kept in the Vatican library (MS gr. 747, fol. 78v). The relevant figure is reproduced in R. Ousterhout (1999, fig. 96). 69 These moulds were made of timber according to A. Kazhdan (1991, p. 322). 70 See D. de Bernardi Ferrero (1984, p. 436). 71 See R. Ousterhout (1999, p. 128). This location of the sites of brick production outside the city but not very far away from it for obvious reasons seems to have been recommended by legislators in the 14th century. 72 See R. Ousterhout (1999, p. 129). These kiln remains are very similar with others from Greece, and Ukraine. Most of these kilns have an oval or a rectangular shape and a surface that does not exceed 15m2.

73

The bricks used in the basilica behind the early Apse of St. Mary measure 31x31x5 cm. Other brick sizes of the same monument are 34x34x4.5cm (Southwestern Pier), and even 36x36x4cm (apse). 74 See J. B. Ward-Perkins (1994, p. 347), and R. Mainstone (1988, p. 69). 75 The average thickness of the bricks used in the earlier, eastern part is 5cm, while the bricks of the western part are 4cm thick. However, it is unlikely that this difference reflects a tendency of brick thicknesses to decrease. As H. Dodge has suggested, in general, “the brick thicknesses in Asia Minor remain remarkably consistent and are on the whole greater than those used in Rome”. See H. Dodge (1987, p. 113). According to A. Kazhdan (1991, p. 323) brick size is not a good dating criterion for buildings.

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Building Materials

34. Ephesos, St. John. Detail of vault fragment A exhibiting finger marks on the brick surfaces.

35. Philippi, Basilica B, brick fragment with finger marks on its surface.

31

Early Byzantine Vaulted Construction in the West Coastal Plains and River Valleys of Asia Minor respectively.76 Also, in some cases, voussoir bricks closer to the springing of an arch or a vault tend to be thicker than the ones used closer to its key.77

One of the letters of Saint Gregory of Nyssa to the Bishop of Iconium, dating back to the late 4th century, and referring to the prospect of building a Martyrium at Nyssa, in Cappadocia, gives us an excellent overview of the use of stone in a church: “the stonecutter’s task” writes the Saint “is not only for the eight piers, which need to be adorned with a beautiful facing, but the task also requires moulded bases on square plinths, and capitals sculpted in the Corinthian style. In addition, there will also be a surrounding portico not less than forty columns, these also of stonecutter’s work throughout”.82 This 4th century specification is astonishing for its remarkable precision and thoughtfulness, so atypical of its time.83 Although it refers to a monument in Cappadocia, it also reflects the wide use of cut stone observed in the churches of west Asia Minor. Nevertheless, it is questionable whether the ample use of stone in the churches can be used as evidence for the activity of early Byzantine quarries. Indeed, although a series of marble architectural elements demonstrate that quarries like the ones of Proconnesus, Aliki, and Ephesos were still being exploited, most of the dressed stones, and especially the ones used in piers, seem to derive from earlier buildings. All these reused elements, or spolia, bearing on them the marks of ancient craftsmanship, serve to remind us that, as the early Byzantine churches emerged, some of the vestiges of Classical and Hellenistic architecture were gradually disappearing.

In St John at Ephesos, bricks intended for vaults have yet another particularity: their large sides have pairs of four long imprints created by the producer’s fingers on the green bricks (fig. 34). The occurrence of similar imprints in the bricks of Basilica B, at Philippi, suggests that they are not a particularity of Ephesos (fig. 35). These long incisions are meant to ensure a better grip and cohesion between the mortar and the brick, a crucial quality in building vaults without centering.78 These marks can still be seen today among the debris of the site, a subtle monument to the expertise and skill of the anonymous early Byzantine craftsman.

2. Dressed Stone and Marble The use of finely cut stone in the Early Byzantine churches of west Asia Minor demonstrates the survival of the older Hellenistic practice of ashlar masonry construction well into the 6th century.79 Of course, buildings like the Ephesian St. Mary show that in the early Byzantine period, the use of fired brick, a cheaper and reliable material, in some cases, came to replace the use of dressed stone even in areas such as pier and wall faces. Still, stone, although much more expensive than brick,80 continued to be used by Early Byzantine builders in many parts of the structure where it was judged to respond better to either structural or aesthetic considerations.81

Structural Uses of Dressed Stone and Marble Cut stone blocks seem to have been primarily used in the faces of piers destined to carry important loads. The best examples of this use are found in the piers at Philadelphia, Sardis, and Hierapolis (see figs. 15 and 19). The same practice is found in Ephesos as well. Still, here, we also find many signs of a tendency to replace stone by brick in pier faces.84 It is rather unlikely that cut stone was used in piers for its aesthetic merits, as it was normally concealed behind revetment, or plaster.85 An exceptional case where the use of cut stone reflects both aesthetic and structural considerations occurs in the piers of the baptistery of St. Mary. The masonry of these piers, consisting of marble blocks adorned with crosses in relief, was meant to remain exposed (fig. 36).86

76 In St. John at Ephesos, these measurements were taken from the double arch that spans the passage between the northern section of the main church and the baptistery’s eastern hall. In St. John at Philadelphia the bricks used in the main arches measure 60x60x4.5cm. The use of larger bricks for vaulting is also observed in Hagia Sophia in Constantinople, where some of the bricks measure 70x70cm (see R. Mainstone 1988, p. 69). J. B. Ward-Perkins (1994, p. 344) has suggested, without any tangible proof, that these bricks must have been specially imported from Rome. 77 A. Choisy (1883, p. 96), has made a similar observation in the vaults of the Boudroun Cistern at Constantinople. According to the French author, “in the same dome the bricks are not uniform. On the contrary, lower bricks have a greater thickness (4 – 5 cm) from the ones that are located higher.” 78 For further comments on the bond between brick and mortar, and its importance in components where the volume of bricks is the same as the volume of mortar, see W. L. MacDonald (1992, p. 11). 79 For more information on the persistence of this building tradition in late Roman Asia Minor, see R. L. Vann (1988, p. 33) and G. R. H. Wright (2000, p. 113). Ashlar masonry is often encountered in the piers of Imperial bath complexes in Asia Minor such as the Vedius Gymnasium, and the Harbour Baths, both in Ephesos (see F. Fasolo 1956, pp. 14–16). 80 The higher cost of stone than brick structures is mentioned in one of our only surviving literary sources documenting Early Christian construction methods: the letter of Gregory of Nyssa to Amphilochius, bishop of Iconium. According to Gregory, “preparation of the stones is not [financially] possible for us. Rather, the material for our building will be clay brick and chance stones.” An excellent translation of the letter can be found in Gregory of Nyssa (2007, p. 200). 81 See J. B. Ward-Perkins (1994, p. 346).

82

See Gregory of Nyssa (2007, p. 201). Indeed, Saint Gregory of Nyssa, writing at the end of the 4th century (and cited in J. J. Norwich 1988, p. 139), deplored the vague and irrational discourse of his contemporaries. He stated: “if you ask a man for change, he will give you a piece of philosophy concerning the Begotten and the Unbegotten (…)”. 84 The piers of St. John the Theologian at Ephesos, for instance, consisted of stone blocks only up to the level of the gallery floor. Our knowledge of the material employed in the upper portion of the main piers of St. John, derives from a pier fragment, which has been illustrated and described in H. Hörmann (1951, p. 95, table XXVI, 1, and 2). Note that the “reconstructive axonometric” published in F. Fasolo (1956, p. 11, fig. 14), mistakenly shows the piers of St. John to be made entirely of ashlar blocks. 85 Traces of plaster still conceal parts of the faces of the northwest pier of St. John the Theologian at Philadelphia. 86 See F. Knoll (1932, p. 47). 83

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Building Materials

36. Ephesos, baptistery of St. Mary, detail of pier facing. The cross in low relief indicates that the ashlar masonry blocks were originally exposed.

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Early Byzantine Vaulted Construction in the West Coastal Plains and River Valleys of Asia Minor

37. Ephesos, St. John, cornice fragments with various profiles.

Well-cut stone blocks were also used to form isolated courses such as cornices, and string courses within brick masonry, and stylobates. Cornices, apart from their obvious role in the articulation of vertical surfaces, often also served to provide a solid, firm footing for the vaulting. Such stone “springers”, often adorned with a moulded undersurface, are observed scattered among the ruins of St. John at Ephesos (fig. 37). They are also found, undisturbed, in their original context, in St. John at Philadelphia.87

The use of ashlar blocks in external walls appears to have been relatively rare. The external walls of the Urban Basilica at Hierapolis, and the north and south walls of St. Mary at Ephesos seem to be the only cases of this particular use of stone in the region (fig. 38). These wall structures owe their existence to exceptional local conditions, and should not be seen as indicative of a general building practice. In St. Mary, the reason was the pre-existence and preservation of a late Roman ashlar masonry structure on the same site.88 At Hierapolis, the use of well-cut stone even in secondary elements was probably encouraged by a local tradition favouring the extensive local quarrying, and use of stone.89 The structure of the “Urban Basilica” displays the influence of this tradition. Here we encounter arches made of stone voussoirs, a feature quite rare for the Aegean area during the Early Byzantine period but standard practice for parts of the Anatolian Plateau, the South Coasts of Asia Minor, and for parts of Syria and Armenia during the same time.90 In western coastal cities like Ephesos on the other

It is not uncommon to find string-courses, made with dressed stone blocks, running through parts of the structure where the construction is otherwise in brick. Such examples are seen both in the external brick wall of St. John at Ephesos and within the brick and rubble piers of St. Mary at Ephesos. In this last instance, the stylobate on which the brickwork rests was made of dressed stone blocks, a more enduring material than brick, especially in an area in contact with the ground’s humidity. 87 The string courses of St. John at Ephesos, of which at least three distinctive profiles have been found, were made of white marble. For a detailed description of the cornices of St. John at Ephesos, see L. Butler (1992, pp. 64–65), and G. A. Sotiriou (1924, p. 94). For the cornice profiles of St. John at Philadelphia, see H. Buchwald (1981, p. 313).

88

See F. Knoll (1932, p. 17), and S. Karwiese (1989, pp. 40–46). See J. B. Ward-Perkins (1981, p. 273). 90 Other examples of vaulted early Byzantine churches with arches made of stone voussoirs are the church of Koja Kalessi, at Alahan Monastery, in western Cilicia, as well as the one of Qasr Ibn Wardan 89

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Building Materials

38. Ephesos, St. Mary, inner face of the external ashlar masonry walls. Note the mason’s mark (an inverted “F”) on the remains of a pilaster on the left, as well as the systematic use of spolia.

The Use of Marble

hand, early Byzantine builders often preferred to use brick and rubble, rather than stone for wall construction. As J. B. Ward-Perkins has eloquently put it, for them “cut stone was an expensive material to be used when needed, but to be used sparingly”.91

Early Byzantine church builders in west Asia Minor must have prized marble both for its strength and its aesthetic qualities. Its full constructional and decorative potential was exploited through its use in nave and atrium colonnades. The systematic use of marble columns as secondary structural elements within the interior of a vaulted church must have been indicative of lavish – and rare – construction. St. John at Ephesos seems to have been the only instance where such an architectural framework, consisting of marble column shafts, capitals and bases, was so developed in the interior of a church (fig. 39). Here, marble members such as bases, shafts, and capitals, the majority of them produced for the church by various quarries, but chosen so that their colours match, were omnipresent. Two-storey marble colonnades surrounded all the central spaces, while a series of marble columns standing next to the walls of aisles and galleries transformed their linear spaces into rhythmic sequences of bays. But, it seems that such an extensive use of new marble members was a rare phenomenon in west Asia Minor. In the interior of other churches, the use of marble columns seems to have been less systematic, involved the use of spolia to a great

Most of the main structural elements where stone has been used (pier faces, external walls, string courses, and vault springings) were subjected to considerable compressive stress. The systematic use of stone in elements that compose the main load bearing system of a church shows that early Byzantine builders were aware of the strength and durability of this material.92 And indeed, despite the “experiments” with brick in the Ephesian churches, stone was the ideal material for heavy pier structures expected to counteract thrusts from wide vaults.

(entrance arches) in Syria. For the arches in Koja Kalessi, see M. Gough (1968, p. 458), and for Qasr Ibn Wardan, see C. Mango (1978, p. 85). 91 See J. B. Ward-Perkins (1994, p. 346). 92 See G. R. H. Wright (2000, p. 113).

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Early Byzantine Vaulted Construction in the West Coastal Plains and River Valleys of Asia Minor

39. Ephesos, St. John. View of the transept showing the diverse elements of support that make up the composite load bearing system: the external brick masonry wall, the ashlar masonry piers and the restored colonnades.

40. Ephesos, St. Mary. View of the early Christian quadriporticus showing the remains of the surrounding colonnade. The central couple of columns of the east portico are flanked by piers, probably in order to emphasize the entrance to the narthex of the church further east.

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Building Materials

41. Ephesos, St. John, detail of pier facing exhibiting holes for the fixing of marble revetment.

extent, and played a lesser role in the structure of the church proper. The areas “par excellence” for the deployment of marble colonnades were the atrium peristyles such as the ones that preceded the entrances of St. John and St. Mary at Ephesos (fig. 40).

were usually made of white marble with a discrete grain. But the purely decorative use of marble was not limited to paving and liturgical furniture. The vaulted basilicas of western Asia Minor demonstrate that Early Byzantine architects in this area followed the late Roman tradition of covering the internal walls of monumental buildings with marble revetment.96 No fragments of this revetment survive today on the site of the churches under investigation.97 The only visible traces of its use are the small cavities on the surface of walls, visible in St. John at Ephesos (fig. 41).98 These cavities betray the existence of iron fixings, (pins, nails or hooks), on which the marble slabs were hung.99 Further indications of the use

The pleasant grain of marble and its attractiveness are probably the reasons justifying its frequent decorative use in exposed elements in the interior of churches. Indeed, excavations at Ephesos have shown that both in St. Mary and St. John, a great number of subsidiary features such as doorframes,93 parapets,94 paving slabs and ambos95 93 Marble doorframes are found in the main narthex entrance as well as in the lateral entrances of St. John at Ephesos. The latter are discussed in M. Büyükkolanci (2000, p. 61). For the elegant marble doorframe inserted in the wall of the outer narthex of St. Mary, see F. Knoll (1932, p. 60, fig. 70 – 71). 94 It is not clear whether parapet slabs such as the ones now found scattered in the sites of St. John and St. Mary divided the nave from the aisles or the chancel from the nave. In St. John at Ephesos and the Basilica of Priene however, the incisions found in the column bases attest that the intercolumniations were blocked by such parapets, isolating the nave from the aisles. 95 Early Byzantine marble ambos have been examined in detail in the Basilica of Priene, as well as in St. John at Ephesos. The ambo of Priene, with its monolithic stairs flanking an octagonal platform raised on columns, and decorated with vine scrolls and peacocks, has been considered by S. Westphalen (2000, p. 279) to be a characteristic

example of a type of ambo limited to the region of Caria and Ionia. At St. John, only the plinth and some fragments of the ambo have been found and moved to their original position at the center of the nave. See M. Büyükkolanci (2000, p. 63). 96 See C. Mango (1978, p. 12). 97 Yet, a very interesting restored example of marble revetment can be examined in the Synagogue at Sardis. 98 For the first observation of these cavities in St. John at Ephesos, see G. A. Sotiriou (1924, p. 108). 99 S. M. A. Hanfmann, (1975, p. 51) states that in late Roman buildings in Asia Minor, “the wall was sheathed with brilliant marble slabs hung from iron hooks over a thin layer of red cement grout [sic]”. According to him, the Greek name for this practice was “ıțȠȪIJȜȦıȚȢ or skoutlosis”, and the Roman one “Opus Sectile”.

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Early Byzantine Vaulted Construction in the West Coastal Plains and River Valleys of Asia Minor

42. Ephesos, St. Mary. View of the door leading from the quadriporticus to the narthex, looking east. Note the reused doorframe as well as the remains of the various phases of the church with the early Christian apse dominating the background. Both doorframe and the flanking walls are 20th century restorations.

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Building Materials

43. Samos, Pythagorion, “Tria Dontia” Basilica, view of the south wall, which includes reused column drums. of marble revetment in the same monument are found in the patchy remains of a pinkish mortar once grouted between wall and marble slab to keep the latter firmly in place.100 So, the pier and wall surfaces of St. John at Ephesos were almost entirely sheathed in marble. But it is questionable whether this practice of “scoutlosis” was typical of early Byzantine monumental building in the region. The preference for frescos rather than marble in Philadelphia, the absence of revetment pin holes in other monuments seem to attest that the marble cladding of St. John at Ephesos reflected more an attempt to revive an earlier building tradition that was, perhaps, associated with Imperial splendour, than a regional building practice. The attempt was successful. Indeed, the decorative use of marble in St. John at Ephesos seems to have stunned its visitors for centuries, and even after the church was turned into a market in the 14th century.101

probably originated in Hellenistic or Roman temples and public buildings. Indeed, in many stone members we observe ornamental details and lewis and cramp cuttings that are either redundantly arranged or simply erratic in their present location. These pieces are often quite varied in size, pattern and texture, and fail to produce uniform structural elements. Such details indicate that these pieces have been reused, and could be characterised as spolia.102 In St. Mary, spolia are abundant. Several of the columns located in the atrium and inside the narthex have different heights, an indication that their column shafts originally belonged to earlier structures.103 Minor adjustments in the height of the pedestals that carried the columns compensated for this mismatch. The majority of the stone blocks employed in the ashlar masonry walls of St. Mary also seem to have been reused.104 Of all the reused elements incorporated in this structure, the one with the greatest impact on its architectural form must have been the elaborate doorframe inserted in the wall of the outer narthex during the second building phase (fig. 42). 105

The Use of Spolia A close observation of the early Byzantine churches of west Asia Minor reveals that a great part of their framework is composed of reused stone elements, which

102

For the use of spolia in Byzantine construction see R. Ousterhout (1999, pp. 140–145), and for an interesting interpretation of the role of reused stone elements in early Byzantine Ephesos, with frequent references to St. John and St. Mary, see I. Leggio (2003, p. 359). 103 See J. Knoll (1932, pp. 41 and 58). According to Auguste Choisy (1883, p. 11), this was a general tendency in Byzantine Architecture: “souvent les Byzantins remployèrent des futs de marbre arrachés aux édifices antiques.” 104 In the side chambers flanking the early apse of the church, small bricks had to be introduced in the masonry joints in order to make up for the misalignments between stone blocks of different size and origin. 105 See F. Fasolo (1956, p. 9), and F. Knoll (1932, p. 60).

100 These traces were identified by M. Büyükkolanci (2000, p. 62). G. A. Sotiriou (1924, p. 108) has identified a revetment slab and recorded its design. It is a part of the base of the revetment. 101 Two accounts that illustrate the admiration for marble revetment and colonnades are the ones of Ibn Battuta, who visited the monument in 1333 A.D., and of Ludolf von Suchem, which reflects a visit made in 1341 A.D. Both accounts are cited in A. Thiel (2005, p. 108).

39

Early Byzantine Vaulted Construction in the West Coastal Plains and River Valleys of Asia Minor Yet, this appreciation of the aesthetic merits of spolia and their incorporation in the new structure in a way that valorises their ornament is not encountered often in the vaulted churches of west Asia Minor. While the size and geometry of spolia were probably taken into account during their incorporation in the new structure, there seems to have been little consideration for their former role and significance (fig. 43). St. Mary preserves three construction details that could be considered as typical of the early Byzantine manner of reusing building material. In the northern side chamber of the domed church, a reused stone block bares an inscription that the early Byzantine builder totally ignored, embedding the corresponding face in the wall, and hiding it with the overlying masonry. In the chamber south of the eastern apse, we can clearly distinguish a marble piece from a coffered ceiling, cut in half, and set pitched on its side within the masonry (fig. 44). In the southeast corner of the domed church we find a piece of an early Christian parapet with a cross in its centre, tilted and cut in order to be used as a cornerstone on the foot of a pier (fig. 45). In all these examples we find that the builder probably reused the pieces in a practical, utilitarian way, without taking into account their former role and meaning, and without care for the symbols on them, either Pagan or Christian. In St. John at Ephesos, the use of spolia is systematic in pier facings, cornices, and parts of the paving. The colonnades were the only part of the structure consisting entirely of elements produced for the church. At least half of the ashlar blocks of the facing of the central piers seem to have been reused.106 Indeed, erratically arranged lewis cuttings and parts of decorative friezes are apparent in the faces of many blocks (fig. 46). The size, tooling, and veining of marble blocks all vary considerably, and, as a result, the pier face often seems like an irregular patchwork of different patterns, colours, and degrees of smoothness. Some of the stone block surfaces exhibit anathyrosis while others do not. Some of the surfaces are rough, with marks of a single point pick on them, whereas others seem to have been further smoothed with a claw chisel. The material reused in this area seems to derive from various earlier buildings.

44. Ephesos, St. Mary, south side chamber of the early basilica. The north wall incorporates a ceiling coffer.

In St. John, the integration of the old material into the new structure was probably done with greater care than in St. Mary. This must have been a laborious but also creative process: in order for the diverse elements to be reassembled into new masonry structures, extensive recarving was required. In the cornices of St. John, this reprocessing of the material must have involved the

106

C. Foss (1979, p. 88), claims that the entire structural fabric of the piers is made of spolia. While this claim could well be correct, I hesitate to follow it in this context. I only identify as spolia pieces on which the existence of redundantly arranged lewis cuttings and erratic ornamental carving leave no doubt as to their origins. However, it is not necessary that all reused pieces exhibit such elements.

45. Ephesos, St. Mary, cross-domed church. Detail of pier facing that exhibits a reused chancel slab.

40

Building Materials creation of new mouldings.107 In other areas, sculptured members were introduced into the structure without any consideration for their particular form. For example, capitals originating in the monument’s pre-Justinianic, and possibly Theodosian phase, were used in the paving of the 6th century building in a way that seems to betray a singular neglect for their sculptural ornamentation.108 At Philadelphia, Sardis, and Hierapolis we also find the usual indications of the use of spolia, but, this time, the latter’s sources seem to have been less diverse.109 Thus, the pier facings consist of few varieties of limestone, and have a more uniform character than the structures at Ephesos. In St. John at Philadelphia, cornice pieces of two different profiles appear side by side on top of the piers (fig. 47). Some of them have been imported from earlier buildings.110 The tendency to use monumental buildings as sources of building material is reflected, more than anywhere else, in the piers of Building D at Sardis. In the heart of each of the colossal piers, one can easily distinguish loose parts of marble pediments, architraves, column drums and cornices, all blended together with mortar in incoherent, inert masses (see fig. 12). We realize that the early Byzantine churches of Asia Minor are real repositories of Classical, Hellenistic, and Roman architectural elements. The question regarding the origins of all this reused material is crucial. The availability of such an enormous amount of spolia, enough to respond to the demand of church construction, has been associated with the decay of a great part of the monumental infrastructure of west Asia Minor in the beginning of the Early Byzantine period. One of the causes of this decay could have been warfare during the 3rd century.111 Another reason for the ruination of monumental buildings could be the gradual redundancy of Theatres, Gymnasia, and pagan Temples, from the 5th century onwards.112 Finally, the frequent destructive earthquakes of the area must have also played a role in the rapid decay of Hellenistic and Roman buildings.

46. Ephesos, St. John. Detail of pier facing with some of its stone blocks displaying anathyrosis, redundantly arranged lewis marks and dentils.

It must have been the combined effect of these factors that turned some of the most impressive and famous monuments of antiquity into sources of spolia. The best 107 Whereas two cornices surrounded the nave of St. John, we can distinguish at least three different profiles within the cornice pieces that lie scattered in the area of the apse. Curiously, L. E. Butler (1992, p. 64) omits to discuss this or to examine the possibility that the cornices consist of spolia. L. Butler’s survey does not take into account the arguments of G. A. Sotiriou (1924, p. 106) according to whom some cornice members were carved out of the taenia of an Ionic entablature. 108 See M. Büyükkolanci (2000, p. 57). 109 For the reuse of stone blocks from earlier buildings in the “Urban Church” of Hierapolis, see P. Verzone (1956, p. 56). 110 H. Buchwald (1981, p. 313), states that all the cornice pieces with the cyma recta profile are reused, whereas the ones with the raking surface profile were created for the church. 111 The invasion of the Ostrogoths in 262 A.D. has been considered responsible for the abandonment of an important part of late Antique Ephesos, including the neighbourhoods around the Temple of Artemis, and the area around the harbour. See C. Foss (1979, p. 3) for further information and an exhaustive list of references. 112 See I. Leggio (2003, p. 368).

47. Philadelphia, St. John, view of the southeast pier from the south, showing a cornice consisting of heterogeneous elements. Below the cornice, the remains of fresco are barely distinguishable.

41

Early Byzantine Vaulted Construction in the West Coastal Plains and River Valleys of Asia Minor

48. Ephesos, St. John. The three different types of stone used in the piers. From left to right: Ephesian white, fine grained marble; blue-grey marble, probably from Ephesos; ochre-coloured limestone. opportunity to study this phenomenon is offered by the Ephesian churches. It is very probable that stone members from the Artemision eventually found their way into the nearby church of St. John.113 Similarly, the external walls of St. Mary were built with stone blocks deriving from the earlier south stoa of the Hadrianic Olympieion, which probably stood in the same location.114 It is not a coincidence that both the Temple of Artemis and the neighbourhood around the Olympieion were severely damaged by the Ostrogoths in 262 A.D.

There were two general attitudes towards earlier sculptural elements: the first championed their skilful integration into the new structure according to their original nature and role, whereas the second, and most frequent, ignored their age value and form, attributing to them no greater value than the one given to any stone block, old or new. Types of Stone and Marble and their Origins Civil war and barbarian invasions during the 3rd century, as well as the growing tendency to reuse building material during the early Christian period, probably inflicted a serious blow to the entire system of marble quarrying and trade in the cities of west Asia Minor.117 However, there are indications that after a pause in marble production, quarrying and supply gradually resumed during the 4th and the 5th century without, however, regaining the level of development they had reached during the Roman period.118 Indeed, our survey seems to suggest that the role of this new produce in the construction of vaulted churches in west Asia Minor was limited. With the exception of St. John, the use of newly produced decorative stone members seems to have been infrequent. In most structures, reused material was favoured.

There have been many attempts to justify the use of Spolia in Byzantine buildings ideologically, and to reflect upon their symbolic potential.115 However, in the early Byzantine churches of west Asia Minor, it is questionable whether the incorporation of spolia in the church structure created the necessary contrast between new and old members for the latter to assume a symbolic significance.116 Instead, most of the reused pieces were inserted in masonry and concealed from view, whereas the ancient members that were displayed (column shafts and doorframes) were not much different from their surroundings. This practice suggests that the motives for the extensive use of spolia must have been above all utilitarian. They were simply a locally available substitute to newly quarried pieces. The reuse of already dressed stone members from proximate buildings that were probably redundant was obviously more economical and practical than to order new elements from the quarries.

In the piers St. John at Ephesos, three types of reused marble blocks are mixed indiscriminately. The majority of them seem to be made of a fine-grained, white marble with a light blue tinge. Here and there, in the same components, we find reused blocks of coarse-grained blue-grey marble with white veins (fig. 48).119 Both these marble varieties are similar to the ones extracted locally

113 See J.-P. Sodini (1989, pp. 165–166). In his survey of the piers of St. John, H. Plommer (1962, p. 127) has identified a Hellenistic marble roof tile, whose big size, reaching 79cm in length, makes it possible for this piece to have been taken from the site of the nearby Temple of Artemis. According to I. Leggio (2003, p. 366), members from the temple of Artemis were not only reused in St. John, but also in the reconstruction of the Harbour Baths in the 4th century, a complex which had apparently also suffered from the late 3rd century invasion. 114 See F. Fasolo (1956, p. 9) and F. Knoll (1932, p. 28). 115 R. Ousterhout (1999, p. 145) mentions cases where the use of Spolia establishes “a symbolic association with the past.” According to R. Cormack (1990, pp. 84–88) the retention of ancient architectural elements and their incorporation within a church building symbolized the victory of the new religion over paganism. 116 See I. Leggio (2003, pp. 374–375).

117

See J. C. Fant (2008, p. 133) for further information about the gradual abandonment of quarries, and evidence for the emergence of a spolia market, after the 3rd century AD. 118 According to J.-P. Sodini (1989, p. 163), only the oriental quarries recovered during the early Byzantine period. Most western quarries, as for instance the ones of Carrara (Luna) in Italy, were to remain abandoned for centuries. 119 In the same piers, we also encounter blocks made of a type of ochre coloured limestone of unknown origin.

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Building Materials

49. Ephesos, St. John. The three different varieties of Proconnesian marble used in the column shafts. St. John at Ephesos offers the opportunity to study the role of Early Byzantine marble quarrying and trade in a major building program. Not surprisingly, in the case of an imperial foundation, the columns of this church have monolithic shafts made of marble quarried in the island of Proconnesus, in the Sea of Marmara.123 This largegrained white marble with blue-grey veins is characteristic of early Byzantine building practice related to Imperial initiative (fig. 49).124 On the other hand, the Ionic bases and impost capitals of the same colonnades seem to have been made of a different kind of marble, of pure white colour this time (fig. 50). This marble lacks the contrast between bands of different colour found in the Proconnesian column shafts. It is possible that some capitals and bases, like several other pieces of white marble found in St. John, (including paving slabs, capitals and bases) are made of Thasian marble.125

in Ephesos, and also appear in the ashlar masonry walls of St. Mary, also in Ephesos.120 Most of the remaining reused blocks in the piers of Building D at Sardis are white and medium-grained. These blocks are very similar to the ones used in the Synagogue and the Gymnasium complex in the same city.121 Interestingly, the further we move from the coasts, the more homogeneous pier structures become. In the facing of the piers of St. John at Philadelphia and the “Urban Basilica” at Hierapolis, there is less diversity in the colours and texture of the reused limestone blocks.122 Possibly, midland sites like Philadelphia and Hierapolis, far away from the sphere of commercial ports, depended on local quarries rather than on a huge, varied stone supply typical of a cosmopolitan port like Ephesos. 120 Indeed, both these two marble varieties can be found in the Celsus Library and the Harbour Baths of Ephesos, and have been identified as Ephesian marble by P. Pensabene, (1977, pp. 134–135). However, according to D. Crouch (2004), Ephesian marble has a wide variety of colours and textures. J. B. Ward-Perkins (1992, p. 154) has noted that the characteristics of this particular marble sometimes make it indistinguishable from other Proconnesian marble. 121 J. J. Herrmann (1993, p. 96), has made the hypothesis that the marble used in the Synagogue’s piers comes from the local quarries of Sardis. However, according to the same author, the colour and veining of this marble are very similar to the ones of the marble of the Aliki quarries, on the island of Thasos. 122 For an identification of the stone used in both the Thermae Basilica and the Urban Church at Hierapolis as a locally quarried limestone, see P. Verzone (1956, pp. 42, 56).

123

For the identification of the marble used in the column shafts of St. John at Ephesos as Proconnesian, see H. Vetters (1973, pp. 183–184). 124 R. Krautheimer (1965, p. 77) explains that the marble quarries on the Proconnesian islands in the Sea of Marmara were run by Constantinople’s Imperial administration. However, J.-P. Sodini (1989, p. 169) notes that, although the exploitation of these quarries was an Imperial privilege, in some cases, the quarry could be rented to a private party. J. B. Ward-Perkins (1951, p. 103), observes that, throughout late Antiquity, Proconnesian marble elements were produced in quantity for a large market. 125 J. J. Hermann, Jr. (1993, p. 96), has identified a semi-finished Thasian Ionic capital (to which we will return) in an area of marble storage to the north of the church. According to the same author, white

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Early Byzantine Vaulted Construction in the West Coastal Plains and River Valleys of Asia Minor

50. Ephesos, St. John. Detail of capital made of white marble with light grey veins (possibly from the quarries of Alike on Thasos or the ones of Ephesos).

Ephesos belonged to the city.130 Even though Imperial patronage may have helped to dispatch marble from Proconnesus to Ephesos, the latter would not have been possible without the existence of mechanisms (standardisation, means of transport) making the production and shipment of marble efficient and feasible. The occurrence of such mechanisms is indicative of the redevelopment of marble trade in the 6th century.131

Nevertheless, the possibility that these same pieces come from local, Ephesian quarries should not be excluded.126 The importation of marbles from quarries as distant as the ones of Thasos, and Proconnesus,127 in a building site surrounded by several productive local quarries,128 may, at first, seem paradoxical. Still, this importation is justified if we take into account the role of Imperial patronage in the building of St. John,129 and the fact that quarries like the ones of Proconnesus were owned and administered by the Imperial authority, while the ones at

The construction of St. John at Ephesos seems to have required an exceptionally large amount of diverse, newly produced marble elements. Signs of a same variety of decorative stones are also encountered in the interior of other churches in the region. In these cases, however,

marble slabs from Aliki, on Thasos have been used in the paving of the apsed hall in front of the skeuophylakion of St. John. 126 J.-P. Sodini (1989, pp. 165–166) states that “in St. John at Ephesos, next to the exported carved elements from Proconnesus, there is a series of pieces made of local marble. These pieces were taken from the Temple of Artemis, and were recarved on the site of St. John”. 127 I estimate the sea journey from Thasos to Ephesos to be as long as the one from Proconnesus to Ephesos, approximately 500kms. 128 For more information on the several quarries around Ephesos, including the ones of Belevi Gölü, see P. Pensabene (1977, pp. 128– 130), and J. C. Fant (2008, pp. 121–135). For the quarries on Panayir mountain, and for the small quarry on the north side of Ayasoluk Hill, very near St. John, see D. P. Crouch (2004, p. 226). 129 For the involvement of Justinian in the reconstruction of St. John at Ephesos, see Procopius, V, i. 4–6.

130

See J. C. Fant (2008, p. 128). For the use of marble from Thasos in Ostia during the Early Byzantine period, see J. J. Herrmann, Jr (1993, pp. 99–101); for late Antique uses of Ephesian marble in Rome see P. Pensabene (1977, p. 136). The wide diffusion of architectural elements of Proconnesian marble in the Eastern Mediterranean during the early Byzantine period has been noted in C. Mango (1978, p.14). For its use in Hagia Sophia, see R. Mainstone (1988, p. 57). Pre-fabricated members of Proconnesian marble also occur in a series of 5th century churches. Two examples are Basilica A, at Nea Anchialos, near Thebes in Greece, and Basilica A, at Alahan Monastery, in Cilicia. See R. Krautheimer (1986, p. 123), and M. Gough (1968, p. 459), respectively. 131

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Building Materials most of the marble elements are spolia. In the basilican hall east of St. Mary, we distinguish reused, fluted column shafts probably made of white Ephesian marble set next to column shafts made of “breccia”, a decorative stone with large, white inclusions in a dark grey matrix (fig.51). A very similar variety of breccia, which also has coarse, white inclusions, but this time in a coral-colour matrix, is found in column shafts in the aisles of the “Urban Basilica” of Hierapolis.132 It is probable that both these colourful members derive from the quarries of Teos, in the west coast of Asia Minor, where breccia of a very similar colour and texture had been quarried between the 1st century B. C. and the 2nd century AD.133 However, a similar kind of breccia, with a characteristic coral matrix (it has been called breccia coralina), was produced in the ancient quarries of Verzirken, in Bithynia, which should also be considered a possible origin of the polychrome shafts at Hierapolis.134 Another question related to the use of marble in early Byzantine west Asia Minor concerns the role of the quarry masons in the carving and shaping of marble components. St. John at Ephesos, apparently the locus classicus for the use of newly produced marble in the region, offers two indications concerning the form in which newly quarried marble members reached the building site. The first indication is given by an Ionic capital spotted in an area for marble storage to the north of the church. The fact that the volutes of the capital are not given a definite form suggests that we are dealing with a semi-finished element. Further evidence concerning the form in which marble products were shipped may be drawn from the following quarry-marks, noticed by G. A. Sotiriou in the cornice members: AcxİǻȘ, cȤİdh ȕ, and cȤİǻhī.135 These marks probably served in the distinction between different cornice profiles and destinations as the members were stacked together after production. Both these unfinished elements and quarry marks suggest that, according to standard Roman and late Antique practice, at least some of the capitals and cornices of St. John were shipped in a “roughed out” condition, in order for their form to be finalized on the building site.136

51. Ephesos, St. Mary, detail of Breccia column shaft. The marble elements of St. John are exceptional both in their quantity and in that, in their majority, they do not seem to be reused. Their production seems to have been associated with an imperially controlled system of quarrying, elaboration and distribution of marble members. This system, in its use of prefabrication and standardisation of products, and in the possible role of imperial administration in it, reminds us of the marble trade organized on mass-production lines during the Roman times.137 And indeed, procurement of marble in St. John at Ephesos may have employed mechanisms not much different from the Roman ones. Yet, the type of marble used in most other vaulted churches of the same region suggests that, in early Byzantine Asia Minor, marble trade had already started to foreshadow future developments such as the generalisation of the use of marble spolia and the abandonment of the quarries after the 6th century.

132 For the identification of the stone of these columns as breccia, see P. Verzone (1956, p. 54). 133 For a description of the two main varieties of marble quarried at Teos, see J. B. Ward-Perkins (1992, p. 157). 134 See R. Gnoli (1971), for a description and further references. 135 For these inscriptions, which mean design a, design b, and design c, see G. A. Sotiriou (1924, p. 10). 136 For the existence of semi-finished Corinthian capitals in the late 5th century Basilica of St. Leonidas at Lechaion, see D. Pallas (1959, p. 131). The same practice of shipping unfinished marble elements that would be further carved on the spot is attested in the building of Hagia Sophia, at Constantinople, where two abandoned capitals with their form simply sketched but not finalized have been found (J.-P. Sodini, 1989, p. 164). We know very little about the origins of the specialized sculptors who would carry out the final carving on site. C. Mango (1978, p. 42) and J.-P. Sodini (1989, p. 163) suggest that these sculptors came from the quarries, according to a late Roman practice studied by J. B. Ward-Perkins, (1951, pp. 93–94). According to this author, Greek quarry-marks and inscriptions found in marbles used in Lepcis Magna indicate that skilled masons accompanied pre-fabricated marble members from the quarry to the building site, carving them in more detail after these elements were properly placed.

3. Rubble Vaulted basilicas in western Asia Minor are characterized by structural components that compete in scale with entire multi-storey structures built next to them in subsequent periods. The reuse of dressed stone members, as well as the use of prefabricated, standardised components and materials such as brick, must have 137

According to J. B. Ward-Perkins (1981, pp. 117–118), marble trade and distribution in this scale begins in the reign of Tiberius. For a review of the process that made marble one of the dominant materials in monumental construction during the 1st century AD, see J. C. Fant (2008, p. 126).

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Early Byzantine Vaulted Construction in the West Coastal Plains and River Valleys of Asia Minor

52. Ephesos, St. John, nave, detail of pier revealing the use of rubble in its core. The use of rubble in the heart of the structure is more limited in the piers of the transept.

53. Sardis, Building D. Southwest pier viewed from the east. Detail exposing the use of mortared rubble in the inner layers of construction.

played a major role in making the building of such gigantic components speedy and economical. The use of rubble, often combined with mortar to form a type of conglomerate reminiscent of the Roman Opus Caementicium,138 must have also been one of the means that allowed Anatolian builders to realize grand scale structures, economising on expensive and timeconsuming ashlar construction. The importance of rough stone fragments for early Byzantine monumental construction and the wide range of uses of rubble are not immediately apparent. This may be because rubble occupies areas in the structure that were to remain concealed after construction, and is only rarely encountered as a facing material.

inert masonry masses behind and above vault shells such as the ones at Philadelphia, Sardis, and, probably, Hierapolis. The angular rubble used in all the above occasions appears to be nothing more than an inert stuffing, loosely tipped between dressed stone blocks, or brick shells.141 In many cases, when the masonry facing containing this inert fill collapsed, the latter was the first element to leak, as it were, from the structure (fig. 53).142 It seems that the friable nature of rubblework did not always deter church builders from using it. Indeed, in some churches, rubble has been combined with mortar to form rubble masonry bands. In St. Mary at Ephesos, the use of rubble in banded masonry has been recorded in the perimeter walls of the baptistery, as well as in the west and east walls of the narthex.143 The only use of roughly worked stone in the entire facing of pier structures occurs in the small vaulted Basilica south of the Theatre of Priene. Piers with part of their facing consisting of rubble masonry also occur in the skeuophylakion, and the baptistery of St. John at Ephesos (see fig. 11).144 In the same church, rubble masonry bands are encountered in the retaining walls of the atrium, in the eastern external walls, as well as in eastern buttresses and outbuildings. The use of rubble masonry was not limited to cities like Ephesos and Priene. Indeed, recent finds showed that the use of rubble also seems to have played a major role in the construction of the external walls of St. John at

The Use of Rubble Rubble in combination with mortar has had a great variety of applications in the churches of Early Byzantine Asia Minor. It was used mainly as an inert, space-filling mass, in pier, wall, and vault cores, and only secondarily in wall facings. In St. John at Ephesos, as well as in the “Urban Basilica” of Hierapolis, rubble set in thick mortar was used to fill small voids between dressed blocks in the core of the pier (fig. 52). A similar, but more extensive use of the material is found in the piers of church D at Sardis.139 The cores of the piers of both St. John at Philadelphia and St. Mary at Ephesos are filled almost entirely with small, rough stone fragments set in mortar.140 A similar mortared rubble fill was used in the

in Chapter 5, this claim is not entirely correct. In the core of the vaults, mortared rubble alternates, in fact, with bands of stone and brick masonry. Such bands may well occur inside the piers as well. 141 J. B. Ward-Perkins (1958, p. 83) describes Anatolian concrete as an incoherent, inert fill. 142 According to C. Mango (1978, p.10) “in Byzantine construction the rubble core does not achieve a homogeneous mass and is kept together by the facing; without the latter, it tends to disintegrate”. 143 For a description of the narthex and the baptistery walls see F. Knoll (1932, pp. 37, 47). 144 For the use of rubble masonry in St. John at Ephesos, see A. Thiel (2005, p. 112).

138 For a definition of Opus Caementicium as “a combination of mortar and lumps of aggregate (Caementa) laid in roughly horizontal courses, see J. B. Ward-Perkins (1981, p. 98). 139 In the core of the piers of Building D at Sardis, the network of dressed stone blocks seems to be less dense, and mortared rubble occupies extensive areas. 140 H. Buchwald (1981, p. 318) states: “the basic structural system of St. John at Philadelphia [is] composed of a mortared rubble core faced below by ashlar masonry and above by brick vaulting”. As we will see

46

Building Materials Philadelphia. In using rubble as a material in its own right in heavily stressed elements, Anatolian builders took a number of precautions, such as its confinement between brick bands, and the careful working and assembly of pieces in such a way so as to form horizontal courses between them.145 The Nature and Shape of Rubble Rubble often consists mainly of a wide variety of coarse stone fragments, either collected from the surrounding landscape, or constituting a by-product of stone cutting for construction purposes.146 Thus, in the rubblework of most churches, we often find fragments of the very same marbles and limestone used in their construction, mixed with small fieldstones. In some cases, for instance in masonry facings, what we characterize as “rubble” consists, in fact, of roughly worked stones laid in courses. Also, as the cases of building D at Sardis, and of St. Mary at Ephesos demonstrate, brick, tile, and pottery fragments may also be part of what we recognize as rubble. The length of rubble fragments varies considerably from 5 cm to 40 cm. Larger fragments tend to be used in coursed rubble construction appearing in wall facings, and smaller ones are used where rubble plays the role of an infill in the cores of walls, piers and vaults. If stone was workable then the rough shaping of blocks and the formation of courses became possible. However, in cases where the stone was intractable, the builder had to use either uncut fieldstones or splinters, randomly placed in the wall structure.147 In this last case, the overall coherence and strength of rubblework relied on the bonding brick courses and on the binding quality of the mortar in which the chips of stone were loosely set.

54. Ephesos, St. John, view of one of the south buttresses, displaying mortar joints of various thicknesses.

4. Mortar Mortar played a major role in early Byzantine church construction in west Asia Minor. This was not only because the coherence of most masonry elements and vaulted shells relied extensively on its binding properties, but also because of its considerable volume within the church structures.148 The liberal use of mortar in brickwork is reflected in the nearly volumetric equality of bricks and mortar joints: in most churches, the ratio between their respective thicknesses is 1:1, and, in some cases, it reaches 2:3 (fig. 54).149 This must have meant that the mechanical properties of brickwork would have been highly dependent on the characteristics of the mortar.

We tend to associate early Byzantine construction with the use of brick and mortar. Still, we find, that, in Asia Minor, the use of rough stones is also extensive, and could be considered as one of the most interesting aspects of church construction. The presence of a material mostly found in vernacular construction in the structure of buildings as monumental as St. John and St. Mary at Ephesos may at first seem paradoxical. Still, it is typical of a construction practice where sophisticated and technologically advanced uses of materials, resulting from the development of late antique building methods, are combined with techniques whose rough simplicity prefigure medieval construction.

The composition of mortar was not uniform throughout the structures, but adjusted to suit different purposes in different parts. In the following paragraphs we will focus mainly on the examination of the mortar used in the joints of load bearing brickwork, and brick vault fragments. The

145 For the use of brick masonry bands to improve the coherence of mortared rubble see A. Choisy (1883, p. 8). 146 The use in Sardis of rounded, seemingly water worn stones suggests that part of the aggregate were riverstones. According to R. L. Vann (1989, p. 17) in the wall of Building A in Sardis “…mortared rubble consists of fieldstones or river stones combined with any other aggregate to be found nearby: cut stone, brick, tile, and pottery fragments.” 147 J. B. Ward-Perkins (1958, p. 88) observes that in the palace of Galerius at Thessaloniki, the schist-like rock used “splintered but would not cut. It had to be used in bands composed not of a number of single courses but of two or three more substantial layers of rubble and mortar”.

148

The use of such a big quantity of mortar has led W. L. MacDonald (1992, p. 12) to suggest that early Byzantine builders must have regarded as concrete what we now tend to see as brickwork. This suggestion seems to overlook the role played by the creation of horizontal joints and the staggering of vertical joints in the structure’s stability. 149 According to C. Mango (1978, p. 10) excessive mortar joint thickness resulted from the need to economize on bricks.

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Early Byzantine Vaulted Construction in the West Coastal Plains and River Valleys of Asia Minor

55. Sardis, Building D, exposed inner layer of the pier structure. The aggregate used in the mortar consists of crushed brick. Note the variation in the size of brick pebbles.

56. Ephesos, St. Mary, early Christian basilica, detail of the north flank of the apse exhibiting mortared rubblework. The mortar here has a grey colour, which indicates the use of volcanic sand.

ocular observation of the colour of the binder, as well as of the size and colour of the aggregates, can offer important information about the composition and qualities of building mortar used in our group of churches. The interpretation of the colour and texture of mortar will be assisted by the results of the mineralogical analysis of mortars from Hagia Sophia at Constantinople,150 Hagia Sophia at Thessaloniki,151 and St. Vitale at Ravenna.152 Finally, our brief examination of Byzantine mortar production, as it is recorded in Middle Byzantine, literary sources, can also improve our understanding of the properties of the mortar used in early Byzantine west Asia Minor.

crushed brick, and brick dust. Even though the exact proportional ratio between binder and aggregate in our churches cannot be determined by an ocular examination, it might be useful to consider that in other early Byzantine churches, this ratio has been found to vary between 1:2 and 1:3.153 The sand and brick particles chosen in most cases seem to have had angular shapes, and a wide variety of sizes that allowed them to fit closely together within the mortar mixture.154 The use of crushed brick as aggregate seems to have been a consistent characteristic of the mortars used in the churches of west Asia Minor. Still, a close examination of these mortars shows that several variations occur in the composition of their aggregate. In the external walls of

Types of Lime Mortar The observation of the colour and texture of mortar joints in most churches seems to suggest that mortar used must have been made from slaked lime and aggregates such as limestone and quartz (in the form of pebbles or sand),

153

For the recommendation of this ratio (1:3) by Vitruvius (where he refers to mortar with crushed brick) and its use in late Roman concrete used in vaults, see L. Lancaster (2005, p. 58). The binder/aggregate ratio in the mortar of Hagia Sophia at Constantinople is approximately 1:2, and the one of St. Vitale in Ravenna, 1:3. For Hagia Sophia, see A. Moropoulou (2006, p. 642). For St. Vitale, see L. Binda et al. (1996, p. 307). 154 The aggregates used affect to a great extent the properties of the resulting mortar. A lime mortar without sand would contract to such an extent in relation to its original volume that its use would probably become impracticable. Added sand reduces the amount of lime in the mixture limiting its shrinkage. At the same time, the aggregate particles encourage the existence of air in the mortar, acting as air entrainers. This not only facilitates the carbonation of mortar but also enhances its porosity, a characteristic that helps the mortar to “breathe”, avoiding damage because of frost. Finally, aggregates contribute to a great extent to the compressive strength of the mortar.

150 For a mineralogical and petrographical analysis of the mortar of Hagia Sophia at Constantinople, see A. Moropoulou et al. (2006, pp. 643–652). For the preliminary results of laboratory testing of the mechanical properties of this mortar, see R. Mark & A. S. Cakmak (1994, pp. 277–278). 151 The results of the laboratory research into the composition and properties of mortar used in Hagia Sophia at Thessaloniki are published in K. Theocharidou (1992, pp. 94–95). 152 The mortar used in St. Vitale has been thoroughly analyzed and tested by L. Binda et al. (1996, p. 289).

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Building Materials resembles the Italian pozzolans, and differs markedly from the calcareous aggregates used elsewhere in Ephesos.158 The dark colour of this aggregate, combined with the fact that it is so finely ground that we cannot distinguish its granules in the mortar’s surface, suggest that it consists of some kind of volcanic tuff. This material contains a compound of soluble silica, and its presence in the mortar probably gave the latter hydraulic qualities. The early phase of St. Mary seems to be the only instance of the use of such a mortar, so similar to Roman pozzolan mortar, in the region of west Asia Minor during the early Byzantine period. The only other suspected use of volcanic sands in the fabrication of mortar in late Antique Asia Minor occurs in the Roman Imperial Baths in the cities of Elaeusa and Korykos, in Cilicia, structures at least two centuries earlier than St. Mary.159 The determination of the mineralogical characteristics of this particular mortar would be of crucial importance not only because of its rarity, but also because of the importance of the building in which it is encountered.

St. John at Ephesos, as well as in the apse of the domed phase of St. Mary, the overall colour of the mortar is warm grey with an ochre tinge. The aggregate used in this mortar is composed of a small percentage of brick pebbles and dust, as well as by a larger amount of quartz pebbles, or other siliceous stone nodules. The latter, in spite of their dark greenish colour, glitter like crystals. Some of the brick and stone nodules are often large enough (2 – 6 mm) to be visible in the surface of mortar joints. In the piers of Building D at Sardis, the composition of the mortar seems to be slightly different. Here, the predominance of brick pebbles and powder in the aggregate and the quasi-absence of other types of gravel are betrayed by the strong pink colour of the mortar and the high density of brick pebbles in its surface (fig. 55). The presence of fired clay in the aggregate must have given the mortar of these churches hydraulic properties. Thus, the mortar was able to set in particularly humid environments. This was an obvious advantage for mortars used in the airtight depths of piers and vault cores. The addition of fine brick powder results in mortars that harden more rapidly, and attain higher strengths than air lime mortars with stone aggregates.155 However, it is not certain that the presence of crushed brick in the mortar of our churches sufficed to give the former the same hydraulic properties as those given by the natural pozzolans used by the Romans around Naples and Rome. Indeed, an aggregate like the one in St. John at Ephesos, where brick nodules with a diameter of 6mm were prevalent, probably did not have the porosity and the surface area needed to develop an eminently pozzolanic action. Although this seems to be a weakness, in our churches, the use of such a moderately hydraulic mortar could also prove to be a blessing in disguise. Indeed, the analysis of such a mortar used in S. Vitale has shown that it is ductile, and has the ability to adapt itself to large deformations without failing.156 This quality was probably very useful in structures like St. John and St. Mary at Ephesos, which are exposed to frequent, and severe earthquakes.157

Mortar Production It is not certain whether the hydraulic qualities of mortar used in the early Byzantine churches of west Asia Minor always relied entirely on the use of pozzolanic additives. The burning of limestone with more than 8% clay content would also have resulted in the creation of a hydraulic lime without the use of an aggregate rich in soluble silica, such as brick dust, quartz, or volcanic ash, being absolutely necessary.160 The form in which such a naturally hydraulic lime can be stored is different from the one of white, non-hydraulic lime. Therefore, the choice of limestone with important clay content would not only have influenced the qualities of the final product but would also have affected lime production in general. A series of literary sources offer important information about lime mortar making in Roman Italy. References to lime production also occur, though often indirectly, in middle- and late Byzantine religious texts and accounts from Asia Minor and Greece. Although none of these sources dates back to the early Byzantine period, they are worth a brief examination, as they are likely to refer to lime-making practices similar to the ones we are investigating.

Crushed brick was not always the only hydraulic factor in mortar. In the remains of the early phase of St. Mary, namely in the walls of the east apse and the piers of the baptistery, the mortar has a characteristic dark grey colour, a feature that is not encountered in other churches (fig. 56). According to F. Fasolo, this mortar consists of white lime and of a finely ground black aggregate that

Romans tended to use pure limestone (with less than 8% clay content) as their basic raw material for lime making. After slaking, and, possibly, after long periods of air-tight

155 See R. Mainstone (2001, pp. 53–55) and L. Lancaster (2005, pp. 51– 52). 156 As research in the mortar of St. Vitale has shown (L. Binda et al., 1996, p. 307), when fired clay appears predominantly in the form of large nodules (with diameters around 4mm) its surface area is not enough for it to develop a fast pozzolanic action. For this reason, the mortar in Ravenna must have been slow-setting. It also had a relatively low strength. Yet, it also had an asset: it was ductile, something that allowed it to deform without cracking. 157 For the contribution of ductile mortars on the earthquake resistance of Byzantine monuments, see A. Moropoulou et al. (2006, pp. 643, 648).

158

See F. Fasolo (1956, p. 3). See J. B. Ward-Perkins (1981, p. 305). 160 During the calcination of limestone containing a proportion of clay in temperatures around 900oC, reactive silicates are formed in the kiln. The slaking that follows results in the creation of a mixture containing both calcium hydroxide (Ca(OH) 2) and reactive silicates (SiO2). Parts of these materials react together, without air (CO2) being involved. The reaction that takes place is the following: Ca(OH) 2 + SiO2 o CaSiO3 + H2O This reaction makes possible the setting and hardening of hydraulic lime in wet conditions, without the presence of air being required. 159

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Early Byzantine Vaulted Construction in the West Coastal Plains and River Valleys of Asia Minor storage in pits, the resulting lime putty would be mixed with aggregate, which often had pozzolanic properties.161 The 10th century testament of St. Nikon, and the surviving 11th account of the building of a monastery on Mount Galesion near Ephesos, both seem to suggest that the same practice kept on being followed in Middle Byzantine Greece and Asia Minor.162 Both these documents refer to the process of burning limestone in kilns, and slaking quicklime in a pit. The testament of St. Nikon, in particular, alludes to the preservation of white lime putty in pits.163 This would only have been possible if lime putty had resulted from the slaking of quicklime resulting from the calcination of pure limestone. Auguste Choisy has claimed that, in case pure limestone was too expensive or could not be found, Byzantine builders resolved to use limestone with clay content.164 That raw material would have given hydraulic mortar that could not have been preserved after its slaking, in the way that non-hydraulic lime putty is preserved (in air-tight environments). The slaking of such mortar probably took place right before it was used in construction. If such a kind of lime was used, as A. Choisy claims, but could not be prepared on site, then it would not have the form of lime putty but the one of a dry hydrate powder, resulting from an intentionally incomplete slaking process. Such a powder could be stored without the fear of premature setting and would have to be carried to the site in containers.165 The use of such a powder in the fabrication of Byzantine mortar, characteristic of 19th and 20th century practices, although possible, is not explicitly confirmed by the sources available to us. Even if the account of A. Choisy is correct, it is not necessary that this same lime making practice existed in the Early Byzantine period. Instead, it is quite possible that, according to Roman building practices, pure limestone was used, the calcinations and slaking of which resulted invariably in a non-hydraulic lime putty.166 The latter assumed hydraulic qualities after its mixture on site with an aggregate such as crushed brick, or other pozzolanic minerals.

161 For further information and references to Roman literary sources concerning lime-making (Vitruvius, Pliny), see J.-P. Adam (1994, pp. 70–74). J.-P. Adam also includes an extract from Cato’s description of the fabrication of lime, taken from De Agricultura, XLIV, De Fornace Calcaria. 162 The references of both documents to lime making have been discussed by R. Ousterhout (1999, p. 133). 163 Indeed, in an incident of the life of St. Nikon, the Savior appears accusing the lime supplier of hiding large quantities of lime putty in his house. See J. Thomas and A. C. Hero (2000, p. 318). 164 See A. Choisy (1883, p. 7). 165 R. Ousterhout (1999, p. 134) refers to a document of 1423 from the Iviron Monastery at Mount Athos containing specifications for the repair of a fountain in Thessaloniki. This document mentions that 7 buckets of lime were required. Still, it is not clear whether these buckets contained dry hydrate lime powder or lime putty. 166 Findings in Pompeii include amphorae full of lime putty. See J.-P. Adam (1994, p. 75).

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detailed information about it. In addition, books devoted to the better-preserved and documented middle Byzantine construction include very few references to early Byzantine Asia Minor.171 Reports on the churches of the region, where available, often seem to contain valuable observations about their building techniques. However, these observations are not always accurate.172

Chapter 2 The Load Bearing Structure: Piers, Walls, and Columns

A comparison between the publications of J. B. WardPerkins and the ones of G. R. H. Wright, demonstrates how our present understanding of early Byzantine construction continues to rely on observations made more than 50 years ago. The above literature review demonstrates the need for a new, in depth survey of early Byzantine load bearing structures in west Asia Minor. This task does not only require the detailed observation of the monuments, but also calls for a new approach to the study of early Byzantine construction techniques. One of the problems of this research is terminology. Terms such as “mortared rubble”, “concrete”, and “pure brick masonry”, have been used in structural descriptions but, perhaps, not always with the same correctness.173 The following examination will assess the extents to which this terminology can be used to define the products of a local building practice, specifically the one prevailing in western Asia Minor.

1. Introduction The load bearing elements of our churches, such as walls, columns and piers are relatively well preserved. This facilitates our task to study the techniques employed in their construction. Almost all the structures examined synthesize three distinctive techniques of masonry construction: rubblework, brickwork, and ashlar masonry. This chapter is organized in sections that deal with these techniques separately. Each section examines the application of each technique to walls and piers, the primary load bearing elements. The chapter is completed by a structural survey of columns, with a particular emphasis on the connections between column bases, column shafts, and capitals. The role of these often delicate, slender elements could be considered as secondary within load bearing systems consisting of heavy piers and walls. Still, as we will see, their incorporation into the structures called for the use of advanced construction methods, which deserve to be considered alongside the main building techniques employed.

2. Rubble masonry Load bearing structures made of rubble masonry rhythmically alternating with bands consisting of multiple brick courses have long been considered one of the most characteristic aspects of late Roman and Early Byzantine building practice.174 Such wall and pier structures appear in four out of the six main vaulted churches in west Asia Minor. The combination of rubble and brick masonry is found in St. Mary and St. John at Ephesos (see fig. 10). The use of pure rubble masonry without brick bands also occurs in the region, in the small vaulted basilica of Priene. The fact that St. John’s skeuophylakion (see fig. 11), where this technique has been used, is dated to the end of the 6th century seems to imply that mixed wall structures kept on being built well into the Early Byzantine period.175 This confirms the persistence during

The following paragraphs aim to contribute to an area of research that, with a few exceptions, does not seem to have received as much attention as it deserves. The pioneering publication of A. Choisy, which served as the introduction to Byzantine vaulting techniques for many generations of scholars, unfortunately devoted less than fifteen pages to load bearing systems.167 Until recently, our knowledge of early Byzantine walls and supports relied extensively on the work of researchers who specialize in late Roman, and not in Byzantine construction.168 For further information into early Byzantine building techniques the reader had to turn to surveys of Constantinopolitan buildings.169 Occasional references to early Byzantine construction have been recently made in publications that deal with a more general subject.170 Although this research helps to see early Byzantine construction in context, it seldom offers

171

See R. Ousterhout (1999). For instance, A. Thiel (2005), in his survey of St. John at Ephesos, fails to acknowledge the constructional differences between the piers of the transept and the piers of the west cross arm. H. Buchwald (1981, p. 301) has not noticed the detailed form of the core of the piers of St. John at Philadelphia, omitting any reference to the existence of ashlar masonry bands in them. 173 The problem of terminology has already been noted by G. R. H. Wright (2000, p. 130). 174 For the use of rubble and brick masonry walls in late Roman Pergamon, Ephesos and Sardis, see M. Waelkens (1987, p. 95–97). In Constantinople, the combination of the two types of masonry in the construction of banded walls is found in the early walls found in Ankara Caddesi, as well as in the remains of the external wall of the first church of Hagia Sophia. Both structures have been described in J. B. WardPerkins (1958, pp. 62, 64). 175 See M. Büyükkolanci (2000, p. 74) for a late 6th century dating of the skeuophylakion of St. John, and A. Thiel (2005, pp. 103–109), for a 172

167

See A. Choisy (1883, p. 7–18). See W. MacDonald (1958, p. 2), and J. B. Ward-Perkins (1958, p. 58). 169 See F. W. Deichmann (1956, pp. 19–41, 84–95), and R. Mainstone (1988, pp.173–176). 170 See G.R.H. Wright (2000). 168

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Early Byzantine Vaulted Construction in the West Coastal Plains and River Valleys of Asia Minor

57. Ephesos, St. Mary, Narthex. Axonometric view of rubble masonry wall, showing the use of thin stone slabs (drawing by Nikolaos Karydis, 2007). as an inert fill, often between more solid structures.177 The properties of this material depend largely on the quantity and quality of mortar used. Rubble masonry also consists largely of rough stones. Still, in this case, the latter form horizontal courses. Mortared rubble consists of elements (rubble and mortar) tipped loosely between stronger, more coherent masonry faces. Rubble masonry, on the other hand, is built sequentially, each course being completed before the next was begun and therefore traversing all of the structure’s width (fig. 57).178

the early Byzantine period, of a construction system that also characterizes Middle and Late Byzantine building practices in the same region, and that seems to constitute a “golden thread” running through the phases of Byzantine building activity.176 Types of Rubble Masonry and Mortared Rubble In our churches it would be necessary to make the distinction between mortared rubble and rubble masonry. Mortared rubble is a loose mixture of fieldstones or roughly worked stones, randomly set in mortar and used

177

See J. B. Ward-Perkins (1994, p. 328) for an excellent definition of the term. Mortared rubble is not a Byzantine invention. J. - P. Adam (1994, p. 57) refers to the Romans’ constant and widespread use of Opus Caementicium, which is also characterized as “an all-purpose fill unrelated to its outer appearance” or facing. Still, there are important differences between the two techniques. These are summarized, with further references, by M. Waelkens (1987, p. 95). 178 See J. B. Ward-Perkins (1958, p. 82).

dating to the period between the late 6th century and the beginning of the 8th century. 176 According to C. Mango (1978, p. 10) the normal system of rubble and brick persisted throughout the Byzantine period.

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The Load Bearing Structure: Piers, Walls, and Columns In some cases, we find a combination of rubble masonry and mortared rubble. The faces of such a structure are made of rubble masonry. The horizontality and straightness of joints, as well as the quality of stone cutting tend to be reduced as we move from the facing to the core. Thus, in the centre of the wall, the masonry structure, consisting of irregular stones and mortar, seems to “degenerate” into mortared rubble, which, however, still follows to some extent the horizontal coursing of the faces. In this case, the faces are the main supporting elements, whose overall cohesion does not rely solely on mortar, but also on the disposition and alignment of stones themselves.

We mostly find it in supplementary elements and additions, probably made hastily during reconstructions, and consolidations. However, in churches of a smaller scale, and in buildings such as Baptisteries, the use of rubble masonry in conjunction with brick masonry bands becomes systematic, and it even occurs in elements that carry major loads. In the west and east walls of the narthex of St. Mary at Ephesos, the stone blocks used are cut to a roughly rectangular shape, and form well defined courses. It is doubtful whether the builders employed brick reinforcement in this wall.182 Instead, there are many traces of flat stone slabs, which form a thin horizontal course 1.00m over the ground. It is quite possible that single courses of flat stones were used regularly, alternating with rubble masonry, and constituting a substitute to brick. These flat stones probably derive from the late Roman building that preceded the early Christian, columnar basilica (fig. 57).183

Brick Masonry Bands The alignment between stones and the use of a strong mortar were probably not considered by early Byzantine Anatolian builders to give sufficient strength and coherence to rubble masonry structures. It is likely that they came to this realization experimentally, by observing the formation of dangerous diagonal cracks across the structure after serious earthquakes, a frequent phenomenon of the area around Ephesos, Sardis, and Hierapolis.179 The builders may have also been aware of the problems associated with the uneven distributions of pressure in structures consisting of rubble masonry skins and mortared rubble cores.180 Perhaps it is these dangers that led them to reinforce rubble masonry with brick bands.

In the baptistery of Saint Mary, rubble masonry alternating with brick masonry bands has been used throughout the outer walls. The brick bands are exceptionally dense: single courses of very rough stones alternate with bands consisting of three brick courses.184 This systematic use of brick bands was probably intended to compensate for the roughness of the rubble used, which made it difficult to form continuous horizontal courses only with rough stones.

Brick bands always seem to run through the entire wall thickness. They consist of two to five courses and occur at more or less regular intervals that range from 20 cm to 80 cm. The number of brick courses is often proportional to the height of the intervening rubble masonry bands (see figs. 10, 11).181

In the church of St. John at Ephesos, masonry consisting of alternating rubble and brick masonry bands occurs in “patches” along the external walls, as well as in the massive buttresses surrounding the transept and the chancel.185 In these cases, there is an obvious tendency to economise on mortar: the gaps between the roughly worked stones are skilfully filled with smaller fieldstones with only a minimal amount of mortar between them (fig. 58).186

This technique combines the use of the most readily available building material, rough stone, with brick, a material whose massive supply and distribution must have also made it a very economical choice. These materials are complementary: the brick, with its geometric structure, adds cohesion to a loose structure consisting of roughly hewn stones, while the stones add weight to the structure. The marriage of the two materials is not only economical, but rational as well.

182

The Austrian Archaeological Institute’s partial reconstruction of this wall on site has introduced a series of bands of two brick courses each, at 30 cm intervals, something that is not confirmed by the examination of pre 1930 photographs of the monument published in S. Karwiese (1989). 183 Such flat stones were used in numerous walls of the earliest phase of St. Mary. We find them in the west wall of the atrium of the church, separating ashlar from brick masonry. They also occur in regular intervals in the facing of the wall of the east apse. For a detailed description of these wall structures see F. Knoll (1932, p. 28, fig. 23) and F. Fasolo (1956, p. 3, fig. 1). 184 For a brief reference to the wall structure of St. Mary’s baptistery, see F. Knoll (1932, p. 47). 185 Such “banded” masonry has often been used to block the building’s openings, such as the ones in the southeast corner and the northwest corners of the transept, and in the east wall of the chancel. A. Thiel (2005, pp. 111–112) gives a very good overview of the use of “banded” rubble and brick masonry in St. John. Reading his dating of the building techniques used in the monument, we realize that this kind of masonry has been used throughout the entire life span of the monument, from the 5th to the 13th century. 186 Similar wall structures occur in the substructures of the atrium, as well as in the unidentified outbuildings south of the chancel of the church. A. Thiel (2005, pp. 104–107) dates the construction of these outbuildings to the 13th century AD.

Case studies Rubble masonry seems to have been mainly employed in secondary wall structures. Its use seems to have been avoided where heavy loads and stresses were involved. 179 E. Altunel (2000, p. 299) states: “the seismic activity of the faults in the area delimited by river Hermos (Gediz), and river Maeander, (Menderes), has provoked, in the course of time, intense earthquakes that have caused serious damages to the cities of the area.” 180 See R. Mainstone (1988, p. 186), and J. Heyman (1995, p. 87). As J. H. notes, “the medieval construction of skin and rubble fill is, with hindsight, a bad practice, but it was universal.” 181 Brick bands consisting of only 2 brick courses, such as the ones of St. Mary, alternate with very short rubble masonry bands (around 20cm); brick bands consisting of five brick courses alternate with rubble masonry bands whose height reaches 80 cm.

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Early Byzantine Vaulted Construction in the West Coastal Plains and River Valleys of Asia Minor

58. Ephesos, St. John, transept wall. Detail of rubble and brick masonry wall. In the foreground, there are remains of parapet slabs decorated with typical early Christian motifs in delicate low relief. The use of “banded” rubble and brick masonry becomes general in the walls of the baptistery and skeuophylakion complex north of the church of St. John at Ephesos. What distinguishes the walls of the baptistery from the ones of the skeuophylakion is the occasional appearance of brick fragments within their rubble bands. In both these two buildings, brick and rubble bands are of equal height.

masonry in piers was also considered in building programmes of a smaller scale.187

3. Solid Brick Masonry A. Choisy and J. B. Ward-Perkins interpret the advent of brick in Anatolian late Roman architecture as the result of the need to find a substitute to Italian Concrete in the construction of vaults.188 The use of fired brick in 2nd century Anatolian vaults which seem to have been directly inspired by Roman Italian precedents seems to support their argument.189 This theory, though credible, does not mean that brick was only a vaulting material.

The external walls of the small basilica at Priene are built almost entirely of rubble masonry. The latter consists of a mixture of reused, dressed blocks and smaller fieldstones, the voids between which are field by gravel, brick fragments, and only a small amount of mortar. This masonry seems to consist of two faces, flanking a very thin core filled with gravel and mortar. Individual stone blocks that run through the entire thickness of the masonry connect the two faces (fig. 59). The use of rubble masonry interspersed with brick masonry bands in the masonry of central piers of the baptistery and the skeuophylakion of St. John at Ephesos may seem as a rare phenomenon in a region where most major piers were regularly made with ashlar masonry facings, according to a practice that goes back to the Roman imperial period. Still, evidence from the vaulted basilica of Priene suggests that the use of pure rubble

187

For the use of ashlar masonry piers in the Baths of Roman Ephesos, see F. Fasolo (1956, p. 14–16). See J. B. Ward-Perkins (1981, p. 276). According to A. Choisy (1883, p. 156) the introduction of fired brick is directly related to the development of vault construction in the region. 189 Early uses of brick in Asia Minor are recorded by J. B. Ward-Perkins (1981, p. 277) in the foundations of the Aspendos Basilica (3rd century), in the dome of the temple of Asclepios Soter (2nd century), and in the entire structure of the Serapeum (3rd century), both at Pergamon, as well as in the library of Celsius at Ephesos (2nd century). 188

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The Load Bearing Structure: Piers, Walls, and Columns

59. Priene, Basilica, view of rubble masonry walls. Note the incorporation of spolia in the wall. The large reused stone blocks are roughly re-cut to fit in the structure.

60. Ephesos, St. John, chancel. View of wall made of brick masonry set on a stone stylobate. The cavity on the wall resulted from the use of timber scaffolding during construction.

Brick was also used in wall and pier structures.190 The best opportunity to study early Byzantine load bearing brickwork in west Asia Minor is offered by the churches of Ephesos.

conformed to a series of common construction principles. These principles guided the way in which bricks were set and “weaved” together, the size of structural elements, and their role in the wider structure.

In the church of St. John at Ayasoluk, the external walls, and the upper portions of the piers consisted of solid brick masonry.191 St. Mary’s structure also makes extensive use of brickwork. Here, the use of brick extends to the entire pier facing. This use is highly exceptional, as pier facings constituted an intensely loaded part of the building, for which the use of dressed stone masonry had been often preferred. This wide use of brick masonry, both in walls and in piers also occurs in the surroundings of St. Mary. Indeed, solid brick structures can be distinguished in walls of the extensive building complex east of the church, as well as in the piers of the baptistery adjacent to the church.

In the surviving brick walls and supports of St. Mary and St. John, the bricks are usually laid in neat common bond, with the vertical joints between them staggered. Still, the accuracy of the construction is often compromised by the lack of uniformity in the joint width and in the brick length. Thus, the vertical joints of each course are not always exactly above the middle of the bricks of the lower course. In some cases, such as the one of St. John’s south wall, the overlapping of courses is approximate (fig. 60). Solid brick masonry consists of a considerable amount of mortar.193 As we have seen in the previous chapter, this is due to the excessive thickness of mortar beds on which the layers of bricks are set. The bed-joint thickness oscillates between 3 and 5 cm. These mortar beds, given their thickness, must play a major role in the structural behaviour of brick masonry. In our survey of St. Mary, we realized that the mortar joints of the earliest phase of the church tend to be thinner than the ones of the later, domed phase.194

The omnipresence of solid bricks walls and piers in St. John and St. Mary may be attributed to the local tradition of brick construction, which had developed in the same city since the late Imperial period.192 The following paragraphs will investigate the basic characteristics of solid brick construction in early Byzantine Asia Minor, by focusing on the use of brick in the piers of St. Mary and the outer walls of St. John.

The thickness of solid brick walls was probably determined by the size of individual bricks, usually around 35cm. It is likely that these dimensions served as a module.195 This is clear in the solid brick structures of

Construction Principles Examining the various brick wall and pier structures of Ephesos, we realize that, despite their differences, they

193

190

The volumetric equality of bricks and their mortar bedding in early Byzantine construction has been noted by various authors. A very good discussion of the subject occurs in W. L. MacDonald (1992, p. 11). 194 According to H. Dodge, (1987, p. 112), “the increasing thickness of the mortar joints with time is an important dating criterion for the brickwork in Rome”. There is not enough evidence to establish whether the thickening of brick joints is a general tendency in west Asia Minor. However, a similar tendency has been noted in early Byzantine Constantinople by J. B. Ward-Perkins (1958, p. 76). 195 See C. Mango (1978, p. 9).

th

For the solid brick masonry walls of the 6 century churches of Constantinople, see R. Mainstone (1988, p. 174) and F. W. Deichmann (1956, pp. 19–41). 191 The quantity of bricks required for the erection of piers that measured almost 4.00x4.00m must have been phenomenal. 192 Indeed monumental bodies of solid brick masonry, such as the ones in the Theatre Gymnasium of Ephesos captivate the visitor’s attention. See F. Miltner (1958, p. 73, fig. 63), and F. Yegül (1992, pp. 251–271).

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Early Byzantine Vaulted Construction in the West Coastal Plains and River Valleys of Asia Minor

61. Ephesos, St. John, axonometric of typical brick masonry wall (cf. fig. 60), showing revetment fragment found by G. A. Sotiriou, 1924 (drawing by Nikolaos Karydis, 2007). St. John at Ephesos: the outer walls of the church, measuring about 1.10m, are three bricks thick, while the south buttresses of the west cross arm of St. John are six bricks thick. This last example shows that even the design of sizeable elements must have taken the size of individual bricks into account.

practice of reinforcing solid brick masonry structures with stone string courses, such as the ones in Hagia Sophia and Sts. Sergios and Bakchos.196 The early Byzantine churches of Ephesos seem to follow this same practice. Here, as in Constantinople, these string courses were made of dressed stone blocks, about 50cm high. Two cases of brick walls where such stone courses can be observed are the east wall of the domed church of St. Mary, as well as the south wall of St. John at Ephesos.

Early Byzantine builders took precautions for the protection and reinforcement of brick masonry. Brick structures seldom reach the ground. Both in St. Mary and St. John at Ephesos, the brick courses are laid upon a stone stylobate (fig. 61). The use of a stone base demonstrates the reluctance of Early Byzantine builders to allow fired brick, desert-dry and eminently porous, to come into contact with the moisture of the ground. Brick is also a brittle material. Both the compressive and the tensile strength of a fired brick are several times lower than the ones of most stones. It is perhaps the realization of this weakness that led to the Constantinopolitan

Case studies: St. Mary and St. John at Ephesos In the piers of St. Mary we encounter the most ambitious use of brick in west Asia Minor. The west piers are divided in two parts, each measuring approximately 3.50x4.20m, interconnected with arches 0.70cm thick, 196

56

See F. W. Deichmann (1956, p. 20).

The Load Bearing Structure: Piers, Walls, and Columns

62. Ephesos, St. Mary, cross domed church. View of the southeast pier from the nave. and c. 3.10m wide (see fig. 4). The east piers have a composite form: they also consist of two parts, of which the ones flanking the sanctuary include chambers with apses, hollowed out in the mass of the piers (fig. 62). Externally, these piers have the appearance of pure brick structures, resting on top of a two-part, moulded marble stylobate. However, what we see from the outside is, in fact, a load bearing brick facing, which is not more than two bricks thick. The core is made of large portions of mortared rubble. In this respect, it resembles the pier cores of St. John at Philadelphia, and Building D at Sardis. There is, however, the possibility that, in some heavily loaded zones, brick courses run through the entire pier thickness.197 Such reinforced zones of pure brick would have helped to compartment the mass of mortared rubble and to provide seating for the broad arches and vaults that interconnected the piers. The thickness of the brick facing, as well as the looseness and incoherence of the mortared rubble core demonstrate that it is the facing that carries most of the loads, with the core being just an inert infill.

Ephesos. According to the general practice, its brickwork is raised on a stone stylobate, approximately 0.50m high. Above this base, the wall is constructed of bricks with relatively narrow mortar joints laid in neat common bond (see figs. 60 – 61). The most interesting features of this wall are a series of cavities that betray the way in which it was constructed, and its original appearance. The smaller holes were probably formed by pins that served to fasten marble revetment slabs on the wall. The larger holes, on the other hand, measuring 12x12cm, probably served in fixing the timber scaffolding. It is likely that this scaffolding consisted of beams embedded on the wall and projecting from both its sides, supporting a platform made of timber planks on which the builders stood. Several platforms were probably erected at regular intervals as the wall rose, and they were probably accessed through moveable ladders.

A typical brick masonry wall, 105cm thick, is found standing 1.20m high on the south side of St. John at

Ashlar masonry construction has been systematically used in the most important components of the churches. Given its frequent use in primary piers, construction with big dressed stone blocks must have been considered the

4. Ashlar Masonry

197 A similar brick structure in the buttress piers of Hagia Sophia at Constantinople has been analysed in R. J. Mainstone (1988, p. 74).

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Early Byzantine Vaulted Construction in the West Coastal Plains and River Valleys of Asia Minor

63. Three ways to lift a stone block. From left to right: with the aid of tenons (handling bosses); using grips (iron forceps); by creating a handle on its top surface using a lewis (sketch by Nikolaos Karydis, 2009).

pick.198 Blocks that exhibit more even, and regular stone faces, on the other hand, must have undergone a finer smoothing, involving the use of wide chisels.199 In St. John at Ephesos, blocks with a smooth surface often exhibit anathyrosis strips, cramp holes and lewis cuttings that are redundantly arranged. This indicates reused blocks. On the other hand, such cuttings are very rare among blocks with a rough surface. Following this observation, I surmise that new stone blocks were roughly dressed. This distinguished them from reused blocks, whose surface, in spite of occasional fissures and various marks, was much smoother, the product of earlier craftsmanship (see fig. 46).200

most capable of responding to considerable loads and lateral thrusts. Although it employed large amounts of reused material, this method of construction must have represented a great challenge for early Byzantine builders: it would not have been easy to manipulate colossal blocks that often weighted more than half a ton. The remains are the only basis for our hypotheses about the construction methods followed to tackle this challenge. In the following paragraphs, these hypotheses are accompanied by a structural analysis of ashlar masonry piers and walls. As we will see, structures made of dressed stone are subject to considerable variation, even within the same church remains. The study of these variations, which ends this section, can throw light in the tendencies that marked the development of ashlar masonry construction during the early Byzantine period.

This does not necessarily mean that early Byzantine stone cutting was inferior to the one of earlier periods. The rough cutting typical of this period was simply adapted to ashlar masonry structures in which the blocks did not need to have a perfectly smooth surface. The perfect smoothing of blocks was structurally and aesthetically essential in the exposed, dry-jointed masonry of earlier times. The same care in stone dressing would have been superfluous in the structures of west Asia Minor, where mortar guaranteed the even distribution of pressure between blocks, and a splendid marble revetment would eventually hide any irregularity.201

Construction Methods Ashlar masonry construction in west Asia Minor relied extensively on a supply of reused and pre-carved stone elements. Although the use of these elements in a new context would have required further work of cutting and smoothing, this work must have been limited to a minimum through the thoughtful placement of reused blocks. Thus, stone blocks deriving from spolia would eventually find their place side by side with newly cut blocks, without causing serious disruptions to the structure.

198

The use of a single point pick in roughing-out the cornice members of St. John at Ephesos has been noted by L. Butler (1992, p. 64). 199 L. Butler (1992) suggests that “claw chisels” were used for the final smoothing. However, according to J. Ayres (1998, p. 81), a wider chisel is required to ensure a finish as smooth as the one in some of the reused blocks of St. John at Ephesos. 200 The existence of a single rough surface in otherwise finely dressed reused stone blocks may indicate their cutting at a later stage to fit in the new structure. 201 The full potential of early Byzantine stone-cutters was not deployed in walls and piers, but in exposed, decorative elements such parapets, and cornices. According to L. Butler (1992) a very smooth carving

The surviving faces of piers resemble a “mosaic” of differently smoothed block faces, both new and old. These blocks display different types of tooling. The rough surface of some blocks bears marks that betray their cutting with a sharp utensil, probably a single point

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The Load Bearing Structure: Piers, Walls, and Columns

64. Hierapolis, “Urban Basilica”, axonometric of typical nave pier (drawing by Nikolaos Karydis, 2008).

whose exact nature is unknown.203 Nevertheless, a close observation of the surface of stone blocks may reveal something of the way in which they were lifted (fig. 63).

A common characteristic of all cases of ashlar masonry is the colossal size of the stone blocks employed.202 A typical limestone block, measuring 100x75x50cm weighs more than a ton. The systematic lifting of such heavy blocks to heights that often reached 7.00m probably required the use of sophisticated lifting mechanisms,

The top surface of most cornice blocks in St. John at Ephesos exhibits dove-tail mortises.204 This type of cutting indicates that a lewis205 was used to get a handle on the stone blocks. However, lewis cuttings are absent in the pier blocks. This suggests that a different method was

assisted by “anathyrosis” ensured the perfect visual connection between the cornice blocks of St. John at Ephesos. 202 The length of individual blocks often exceeds 100cm, their height often averages 50cm and their depth can reach 150cm. In the extramural Church of the Thermae at Hierapolis some pieces exceed 250cm in length, and 100cm in height. G. A. Sotiriou (1924, p. 95), in his pioneering report on St. John at Ephesos, refers to IJȚIJĮȞȩȜȚșȠȣȢ, i.e. blocks of “titanic” size. According to P. Verzone (1956, p. 42) “the modest capacity and strength of local limestone imposed big size elements and the edifice thus assumed a massive character.”

203

J. P. Adam (1994, p. 45) refers to the Roman use of lifting machines such as cranes, winches, as well as blocks and tackles. There is no reason to believe that these machines had ceased to be available to early Byzantine builders. 204 See L. Butler (1992, p. 64). 205 Lewis: A metal instrument with a dove-tail outline consisting of three parts assembled so as to grab hold of a heavy stone block.

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Early Byzantine Vaulted Construction in the West Coastal Plains and River Valleys of Asia Minor used to lift them. Stone blocks may have been simply placed in a sling of rope, chain or webbing. An alternative would have been to hold the stones in grips, or nips.206 Tenons or bosses207 might have also facilitated the lifting of blocks by providing a convenient attachment for the rope slings. The removal of such elements once the blocks were in place could account for the absence of traces indicative of this technique. Still, a series of tenons have been observed along a cornice belonging to the first, Roman phase of the church of the Thermae at Hierapolis (fig. 21).208 The fact that these particular tenons were never removed seems to suggest that this early building was never completed. In many of the monuments, the builders seem to have encountered difficulties in joining the stone blocks together. The blocks were set on their correct bed, with their sedimentary layers horizontal. However, the joints between them often lacked the fineness found in dryjointed, ashlar masonry of previous periods. In the basilicas of Hierapolis and in St. John at Philadelphia, horizontal joints lack straightness and continuity. Sudden interruptions of joints and the creation of “steps” are often due to the use of blocks of different height in the same course. This problem is often resolved either with the proper insertion of small stones, or with the adequate, “L-shape” cutting of blocks. Still, the builders have often neglected the staggering of vertical joints in ashlar masonry. In all churches, there are several cases of long, continuous vertical joints, which are particularly harmful to the cohesion of the ashlar structure. This lack of cohesion is exacerbated by the absence of dowels or cramps connecting the stone blocks together. Perhaps, the binding capacity of mortar made the builders to underestimate the importance of overlapping between the blocks.

65. Philadelphia, St. John, axonometric drawing of the northwest pier, showing core and facing (drawing by Nikolaos Karydis, 2008). Ashlar Masonry Piers The vaulted basilicas of Hierapolis are the only ones to have elongated piers (fig. 64). In all the other monuments, the piers have a more or less square plan, with a footprint size that ranges from 3.5 x 3.5m to 6.7 x 6.7m. The profiles of piers in plan are often characterized by re-entrant angles, which are formed by the projection of pilasters from their main body. The simplest pier profiles are encountered in St. John at Ephesos, and the Urban Basilica at Hierapolis. More complex profiles, with double re-entrant angles, occur in Philadelphia and Sardis (fig. 65).

The thickness of horizontal mortar joints ranged from 0.5cm to 3.0cm. The height fluctuations within single joints were dealt with the insertion of small chips of stone between the blocks and the liberal use of mortar. Although mortar played a crucial role in the strength and coherence of rubble masonry, in ashlar masonry construction, it is not certain that the presence of mortar joints improved stability. Still, there is no doubt that mortar beds guaranteed a homogeneous distribution of loads between blocks, even when their surfaces were not perfectly smooth.209

In some cases, the height of stone courses is stable throughout the structure, in spite of minor discrepancies.210 However, other structures, such as the western cross arm of St. John at Ephesos, and St. John at Philadelphia, depart entirely from the isodomic principles.211 In these cases there is a great divergence between course heights of the same pier. In the case of the Ephesian monument there has been an attempt to maintain the structural uniformity of the structural fabric by creating more or less stable alternations of tall and short courses (see fig. 46).

206 A series of small holes in the faces of the stone blocks of the church of the Thermae at Hierapolis, observed by M. L. De Bernardi (2002, p. 275), reveals that grips were used in the late Roman phase of the building. In most of the blocks of the piers at Ephesos and Philadelphia, there are no holes in which pincers could grip. Still, in rough blocks, the existence of such holes would not have been necessary. 207 Bosses, or, otherwise, tenons: projections on the block, left symmetrically on the front and back faces providing a convenient attachment for the rope slings used for lifting purposes. 208 These tenons are found in the cornice crowning the outer portion of the piers. 209 For the role of mortar beds in Roman ashlar masonry see J. P. Adam (1994, p. 57).

210

Ashlar masonry with courses of equal height is found in the baptistery of St. Mary, in St. John at Ephesos, in Building D at Sardis, and in the Church of the Thermae at Hierapolis. The latter’s structure has been described in detail in M. L. De Bernardi (2002, p. 272). 211 Isodomic construction: ashlar masonry construction consisting of horizontal courses of equal height.

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The Load Bearing Structure: Piers, Walls, and Columns

66. Ephesos, St. John, axonometric of typical pier showing the connection between pilaster and main pier in four different horizontal sections (drawing by Nikolaos Karydis, 2008). The existence of pilasters that project from the main body of the piers is very common (fig. 64). The ways in which these structural projections are realized varies; so does the nature of their bond to the main structural mass. The method of the revealed bond favoured the “L-shape” cutting of stone blocks.212 This created an alternation of courses in which the bond between pier and pilaster is monolithic, and courses in which there is a vertical joint between the two elements. This system of construction is found in the piers of St. John at Ephesos (fig. 66). According to an alternative method, some of the blocks of the pilaster were embedded like “headers”, or “through-stones” inside the piers (Simple Bond). The rest of the courses are composed of “runners”, longitudinal stone blocks that are independent from the pier. This building practice seems to be the most frequent in western Asia Minor. We find it in the piers of St. John at Philadelphia and the ones of the two Basilicas at Hierapolis.

thickness. Such inner blocks were carefully hewn on top and bottom, in order to provide proper surfaces for stacking one upon the other, but remained quite rough on the vertical faces. An economical alternative consisted in limiting ashlar masonry to the faces, with the core being filled with mortared rubble. Such a structure is observed in St. John at Philadelphia. In some cases, we encounter a combination of the two techniques. For instance, both in building D, at Sardis, as well as in the west cross arm of St. John at Ephesos, the pier cores consist of both semisquared stone blocks and mortared rubble. This variation and the existence of such hybrid structures prove that the early Byzantine builder did not always follow predetermined systems of construction faithfully, but modified them to fit his resources and abilities. The piers of St. John at Philadelphia constitute a typical example of ashlar masonry construction in west Asia Minor during the Early Byzantine period. These piers are said to have been “composed of a mortared rubble core faced (…) by ashlar masonry” (fig. 67).214 However, this claim needs to be treated with caution as it refers to a structure that reveals only a small part of its inner composition. The excavation that brought to light the remains of the southwest pier suggests that the builders seem to have dispensed almost entirely with the use of stone blocks in the pier core (see figs. 17, 18). Indeed, the

Even though the form of the ashlar masonry facing of the piers does not lend itself to considerable variation, their cores vary.213 A frequent practice, observed in St. John at Ephesos, and the Basilicas of Hierapolis, was to use equally large blocks of stone almost throughout the pier’s 212 This detail has been observed by R. L. Vann (1989, p. 33) in the late Roman Building C at Sardis. 213 See R. J. Mainstone (1988, pp. 173–174).

214

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See H. Buchwald (1981, pp. 302, 312).

Early Byzantine Vaulted Construction in the West Coastal Plains and River Valleys of Asia Minor partly visible horizontal section of this pier indicates that mortared rubble was the only material used behind the ashlar facing. Still, a detail in the Northwest pier reveals that the mortared rubble core behind the shell of the vaults is interspersed with bands of ashlar and brick masonry. We cannot exclude the conservative use of similar reinforcement in the lower parts of the piers. Even in this case, however, mortared rubble should still be considered as the main material used. These piers, measuring approximately 6.70x6.70m, are the largest known in Byzantine architecture, comparable only with the ones of Hagia Sophia.215 I surmise that the builders of St. John decided to employ such large sections in compensation for the extensive use of mortared rubble, a material that was cheap but also weak. Ashlar Masonry Walls and Pilasters Ashlar masonry walls with an average thickness of 1.2m are often equipped with series of rectangular pilasters that jut out by 60–90cm. There is not always a proper bond between walls and pilasters. In the Urban Basilica at Hierapolis, there is a “timid” attempt to join together wall and pilaster by embedding some of the pilaster’s stone blocks into the wall mass. But even here, these blocks are so few and occur at such wide intervals that they are insufficient to bind the two elements together. In many ashlar masonry walls, the addition of pilasters seems to have been an afterthought. In St. Mary at Ephesos, the continuous vertical joint between wall and plasters, indicative of the fact that the two belong to different phases, does not leave any doubts as to the structural independence between the two elements. Although the pilasters at Ephesos and Hierapolis were meant to assist in the counteraction of lateral thrusts, their discontinuity and lack of bond with the main wall structure undermine their structural function.

67. St. John at Philadelphia. Interpretive axonometric drawing of the northeast pier showing the ashlar masonry facing, the mortared rubble core, and the wall that originally enveloped the building (drawing by Nikolaos Karydis, 2008). foundation, such as St. John at Ephesos, probably benefited from a wider supply of materials and a workforce more numerous and skilled than the ones of more modest churches. Yet, this interpretation cannot explain the use of different types of ashlar masonry in the same church building. In these cases, structural differences may indicate the existence of building phases. The study of these phases in St. John at Ephesos and in the basilicas of Hierapolis illustrates the evolution of ashlar construction during the early Byzantine period.

In the case of the Urban Basilica at Hierapolis, there is also a series of external buttresses, projecting about 50cm, and – in most cases – corresponding to the internal pilasters. These buttresses were joined together by semicircular arches, with stone voussoirs. Thus, an external blind arcade was formed, articulating the external elevations.216

A change of method seems to distinguish the east and the west piers of St. John at Ephesos. In the transept and the chancel, the piers are characterized by an almost uniform course height and the use of squared stone throughout their mass (figs. 68 and 70). The piers of the west cross arm, on the other hand, exhibit courses with differing thickness, and cores that contain areas filled with mortared rubble (fig. 52). This is yet another indication that the two groups of piers must have belonged to different building phases, possibly with an important chronological difference between them.218

Patterns of Development The ashlar masonry tradition in west Asia Minor lent itself to considerable variation. These variations could be interpreted as regional and considered to reflect the different resources available in each site.217 An Imperial 215 The main body of the primary piers of Hagia Sophia measures approximately 8.00x5.00m. The footprint of these piers covers roughly the same area as the footprint of the piers in St. John at Philadelphia. However, the spans in Hagia Sophia, approximately 32m, are three times wider than the ones at Philadelphia. 216 For a description of the pilasters and buttresses of the Urban Basilica at Hierapolis, see P. Verzone (1956, p. 54). 217 For a comparison between St. John at Ephesos, and the Urban Basilica at Hierapolis, accompanied by comments on the “lavishness” of

St. John and the simplicity of the Hierapolitan church, see P. Verzone (1956, p. 60). 218 Judging from the whole series of constructional and morphological differences between the two parts of the church, the length of time between the two phases must have been considerable. The differences in the vaults of the two parts of the church will be discussed in Chapter 3.

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The Load Bearing Structure: Piers, Walls, and Columns

68. Ephesos, St. John, transept, remains of the northwest pier. Dressed stone is used almost throughout the structure.

69. Priene, Temple of Athena Polias (4th century B.C.). Detail of ashlar masonry retaining wall of the podium on which the building rests. Note the setting of blocks without mortar and the fine, hairline joints.

At Hierapolis, the lines of division between phases are not as clear-cut as in St. John. Still, according to P. Verzone, the structures of the two vaulted basilicas seem to illustrate a qualitative deterioration of ashlar construction.219 This deterioration seems to affect the fineness and straightness of joints, as well as the uniformity of masonry. Also, in some parts of the basilicas of Hierapolis, mortar and rubble are used to fill irregular voids generated by the increasing misalignment between dressed stone blocks.

into the early Byzantine period of a very old building tradition, with a very important development during the Hellenistic and Roman periods.220 However, there is a great qualitative contrast between the typical Hellenistic dressed stone masonry, with its fine hairline joints and handsome isodomic finish (fig. 69), and the ashlar masonry seen in our churches.221 In spite of its liberal jointing, heterogeneous mass and recycled material, Anatolian early Byzantine ashlar masonry conserves a role in the structure that links it with previous traditions. The decision to use it follows simple criteria (need for exceptional strength, protection from the ground’s humidity, aesthetic merit of stone etc.) that have also pertained in earlier architectural traditions.

Certain broad tendencies appear to take shape from the available evidence. The growing variation in the height of courses is one of them. The facing of structures tends to differ structurally from their cores. In the latter, the role of mortar rubble becomes more and more important. Another aspect of the increase in the proportion of mortar to stone in the structure is the progressive widening of horizontal joints, which tend to become discontinuous and irregular.

5. Internal colonnades The stylistic survey of early Byzantine columns in west Asia Minor, as it appears in other publications,222 is beyond the scope of the present book. Our interest in columns and colonnades lies more in their structural role and the challenges associated with their construction than in their style. The incorporation of colonnades in a

There is not sufficient evidence for determining whether these trends can be used as criteria for dating the structures. Still, they indicate their building phases. Piers built with large quantities of mortared rubble, and with irregular and discontinuous joints, such as the ones of St. John at Philadelphia, seem to indicate a deterioration of ashlar construction at a late chronological stage. On the other hand, piers entirely built of dressed stone blocks, with courses of equal height, as the ones in the east part of St. John at Ephesos, could be seen as products of an earlier time when the memory of Hellenistic and Roman isodomic construction had not completely faded.

220

For an overview of the various Roman techniques of ashlar masonry (Opus Quadratum, Opus Vittatum, and Opus Saxum) see J. P. Adam (1994, pp. 102, 135). According to R. J. Mainstone (1988, p. 173) “the use of blocks of squared stone carefully fitted together with only a sparing use of mortar [is an] unbroken early tradition”. 221 For a comparison between Hellenistic and Roman ashlar masonry, see G. R. H. Wright (2000, p. 111). 222 The form of early Byzantine capitals in west Asia Minor has received considerable attention. For the Ionic impost capitals of St. John at Ephesos see F. Miltner (1958, pp. 119–122), and R. Kautzsch, (1936, pp. 165–182). A comparison between these capitals and the ones of St. Eirene at Constantinople occurs in W. F. Deichmann (1956, p. 90). For a detailed investigation of the Ionic impost capitals of the Gymnasium of Sardis, see F. Yegül (1974, p. 265–274). Column bases have failed to attract the same attention. Still, references to their carving and profiles occur in J.-P. Sodini, (1989, p. 170) and N. Asgari (1992, p. 74).

The use of large rectangular blocks of dressed stone to construct strong vertical supports shows the survival well 219 For a study of the development of ashlar construction in the successive phases of the Church of the Thermae at Hierapolis see P. Verzone (1956, p. 59).

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Early Byzantine Vaulted Construction in the West Coastal Plains and River Valleys of Asia Minor

70. Ephesos, St. John, Transept. View of southeast colonnade, showing details of stylobate, column bases, monolithic column shafts, and capitals.

64

The Load Bearing Structure: Piers, Walls, and Columns structure like the one of St. John at Ephesos represented a great structural challenge. The setting of marble shafts on edge, and their integration within structures consisting of components susceptible to considerable deformation have both been problematic from a structural point of view.223 The methods developed by Byzantine builders to respond to these issues were essential and deserve to be investigated. The following paragraphs will focus on colonnades inside the churches, as opposed to the colonnades surrounding their western forecourts. Internal colonnades appear in St. John at Ephesos, as well as in the small basilicas of Priene and Pythagorion. Judging from the numerous column shafts, capitals, and bases found scattered in the ruins of St. Mary, it is very likely that a sequence of columns screened its gallery. Although a sequence of piers replaces the colonnades in the “Urban Basilica” at Hierapolis, there are several remains in the debris of the church that must have belonged to individual columns.

71. Ephesos, St. John, detail of stylobate with dowel hole.

The above colonnades seem to have rested on a stone stylobate,224 consisting of dressed stone blocks of various dimensions (fig. 70).225 Part of most stylobates was buried in the ground, and, even now, it is difficult to determine their height. It is probable that their stone blocks were laid directly on the foundations, although the existence of an intermediary stereobate cannot be excluded.226 In the galleries of St. John, it seems that the colonnades rested directly on the cornice blocks.227 The connection between stylobates and column bases was very important. Its role was to ensure the transmission of loads from the column to the foundations. It also had to counteract the sudden shear stresses between column and stylobate, caused by earthquakes. Circular dowel holes found on top of the stylobates of St. John at Ephesos indicate that metal or timber dowels kept the bases firmly in place (fig. 71).

72. St. John at Ephesos, Transept. Detail of typical, Ionicstyle column base. Note that the drum on top of the base is slightly larger than the bottom surface of the column shaft.

The profiles of bases are quite varied. Their form is characterized by a transition between a square plinth at the bottom and a cylindrical drum at the top. This drum was slightly larger than the bottom surface of the monolithic column shaft. As a result, where the column shafts have been reset on their bases, such drums seem to bulge out by a few millimetres (fig. 72).228

distribution of pressure between shafts and bases was a major problem. If the surfaces of the two elements had been perfectly smooth, and if the column shafts had been kept still and vertical at all times, this would have easily been achieved. But this was not the case. The surface of both elements had a certain irregularity, and the columns could not be easily kept upright in a structure susceptible to settlement and subjected to serious earthquakes. Tilting movements threatened to accentuate the unevenness of the bearing pressures, introducing the risk of local spalling, or even splitting under load.229

The seating of column shafts on the bases was probably the most difficult task of the construction. The uniform 223 Indeed, according to L. Binda et al. (1996, p. 307) walls and piers containing an increased amount of mortar could adapt themselves to large deformations in a way that was not possible for stronger, but also brittle columns. The difficulties with marble columns during the building of Hagia Sophia are reported in Procopius, I. i. 75f. 224 Stylobate: a course of dressed stone blocks on which the columns rest. 225 The width of the blocks ranged from 1.00m to 1.20m, and their length varied from 1.00m to 2.00m. 226 For the use of stereobates by the Romans, see Vitruvius, III, 4, 1. 227 See L. E. Butler (1992, pp. 64–65). 228 The diameter of the upper drums of the bases in St. John is approximately 55cm.

In the colonnades of St. John at Ephesos, the risk of such failures was greatly reduced by inserting a lead “seating” between column base and shaft. These lead sheets were kept contained by bronze annulets.230 The profile of the 229

For the occurrence of this risk in the colonnades of Hagia Sophia, see R. Mainstone (1988, p. 67, 208). 230 For the find of the remains of such annulets during the first excavations of the monument, see G. A. Sotiriou (1924, p. 103).

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Early Byzantine Vaulted Construction in the West Coastal Plains and River Valleys of Asia Minor bases and the shape of the bottom of the shafts are indicative of the use of such reinforcement. Similar profiles in combination with the use of bronze annulets are found in the feet of the columns of Hagia Sophia. The presence of thin sheets of lead between shafts and bases had the advantage of guaranteeing an excellent contact between the two elements, even if their surfaces were not perfectly finished. But, more importantly, lead, a ductile material, could also adapt itself to deformations, maintaining an even distribution of pressure even after the slight tilting of the column shafts.231 The bronze collars surrounding the lead joints would not only keep the lead contained but would also prevent the horizontal displacement of the column shaft during an earthquake (fig. 73). It is possible that the reinforcement described above was also used in the placement of the capitals on top of the columns. In other cases, the connection between capitals and shafts was strengthened by metal dowels. The existence of such elements is betrayed by circular holes found on top of shafts as well as on the bottom of some capitals (fig. 74). The form of the impost capitals must have played a major role in the adaptation of slender columns in structures consisting of heavy, sizeable elements. Indeed, although the average diameter of a shaft was often less than 50cm, the smallest arches had a soffit width of at least 90cm. Somehow, the upper bearing surface of columns had to be enlarged. This was achieved by carving capitals with trapezoidal profiles that ensured a harmonious transition from the circular top of the column shaft to a sizeable rectangular platform on which brick arches could seat. The crudeness and simplicity of capitals and bases in our churches can make it difficult to appreciate the full qualities of the structure of columns. However, the measures taken to consolidate the columns and to incorporate them in vaulted structures could be extremely sophisticated and involved the use of ingenious techniques. It is hoped that, by focusing on these techniques, the foregoing survey threw light on an aspect of early Byzantine craftsmanship, which, perhaps, has not yet received the attention it deserves.

73. Constantinople, Hagia Sophia. Schematic drawing illustrating the seating of column shafts on lead sheets (Q) and the use of bronze collars (F) to contain the lead (drawing by Nikolaos Karydis, 2004, after A. Choisy, 1883).

231

The seating of monolithic column shafts on lead joints contained by bronze collars is frequently encountered in Byzantine churches of various periods. One of the earliest modern references to this technique occurs in A. Choisy (1883, p.13). Bronze collars have been observed in Hagia Sophia by R. Mainstone (1988, p. 67) as well as in several churches of Mount Athos. For an excellent illustrated analysis of the structural role of these elements in the main church of Doheiarion Monastery, see P. Touliatos (2009, pp. 64, 67).

74. Ephesos, St. John. Detail of Ionic-style impost capital (upside down). Notice the dowel hole at the top (originally in the center of the base of the capital).

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Part 2 The Vaulted Structure

that has often influenced research into early Byzantine construction.3

The investigation of Early Byzantine vaulting in western Asia Minor has long been impeded by the rarity of vault remains in the area. Researchers aiming to restore the churches’ missing vaults often tend to base their proposals on comparisons with a few contemporary churches with similar plans, which conserve their vaults. Although this comparison seems sometimes to be a legitimate resource when confronted with scanty church remains, it can often prove to be inaccurate or even misleading if used as one’s only base for graphic reconstruction. Indeed, to imply that churches with similar plans had identical vaults is to underestimate the wide variety of Early Byzantine vault geometries and structural fabrics. To consider a priori Constantinople’s vaulted structures as the models for Western Asia Minor’s vaulted construction is to overlook the possibility of local variations in building methods.1

The following chapters aim to reconstruct the vaulted forms of the churches, doing justice to the idiosyncrasies of each monument, focusing on construction details. In these chapters, the information that could be drawn from typological comparisons, in spite of its limitations, is not neglected.4 Yet, here, comparisons only serve as partial evidence for reconstructions, which rely on the remaining fabric of each monument as the primary clue as to the original form of the missing vaults. In my on-site surveys of the churches’ remains I have discovered a series of vault fragments and construction details, whose potential in contributing to graphically reconstruct the missing vaults had until now been underestimated. The following paragraphs demonstrate how the examination and survey of the fragments can form the base for graphic reconstruction. This reconstruction of the vaults of the six churches at the focus of this study, in most cases, has three parts. The first one comprises an analysis of remaining vault fragments, which leads to a series of detailed axonometric sections (1:50 scale) of the areas in which the fragments seem to originate, and aims to give information on the original structural fabric of individual vaults. In the second part, the possible assembly of these fragments is

In order for these variations and local particularities to be fully appreciated, detailed examination of vaulting needs to go beyond that in the recent bibliography.2 The typological classification into “domes on pendentives”, “shallow domes”, and “cross-vaults” is too restrictive. Instead, it would be worth trying to describe vaults analysing their structural tissue. The observation of the actual way in which brick courses are woven together, as well as the understanding of the particular geometry of each vault can unveil the existence of a large variety of vaulted forms, far beyond the limited vault typology

3 R. Krautheimer (1986, p. 238), for instance, claims that Early Byzantine vault designers and builders “…worked with a few basic elements. (…) They shunned complex forms and concentrated instead on barrel-vaults, groin vaults (…), and on pendentive domes and domes on pendentives.” Yet, this argument tends to overlook the amazing variety of structures found within each of the above vault categories. 4 Indeed, the potential of typological comparisons should not be disregarded. The remains of Early Byzantine churches of Asia Minor have often been fruitfully compared to churches like Hagia Sophia, St. Eirene, and Sts. Sergios and Bakchos in Constantinople. The resulting discussion has often been very interesting, especially in cases where such comparisons are used to define the context of western Anatolian building practices. For a good example of such a discussion see H. Buchwald (1981 p. 314, 317). However, the small number of surviving vaulted monuments from Early Byzantine Constantinople makes it difficult to distinguish any repetitive use of vaulting concepts and construction methods, which would have plausibly influenced Asia Minor’s builders. For a similar argument see A. Thiel (2005, p. 46).

1

The first graphic reconstruction of St. John, published by H. Hörmann seems to use the dome of post 558 AD Hagia Sophia as a model. All domes are drawn hemispherical, with the main supporting piers reaching in height the level of the domes’ springing, thus creating “high-shouldered” external profiles. H. Plommer (1962, p. 125) has relied on proportional comparisons with St. Mark in Venice or St. Front in Perigueux, to establish the height of St. John’s gallery. In a similar way, the graphic reconstruction of St. Mary at Ephesos in F. Knoll (1932, p. 61, fig.73) suggests the existence of a dome whose design echoes the dome of St. Eirene in Constantinople. 2 Indeed, in the two latest graphic reconstructions of churches of western Asia Minor, the ones of St. John in Ayasoluk by A. Thiel, Building D in Sardis (unpublished), and St. John in Philadelphia by H. Buchwald (1981, fig. 3) represent vaults only in outline, without offering any information about their structural fabric.

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Early Byzantine Vaulted Construction in the West Coastal Plains and River Valleys of Asia Minor established through the consultation of contemporary written accounts when available, and through comparison with similar monuments. The third part, including sections and axonometrics in a scale of 1:100, builds upon the information gathered in the first stages, representing possible versions of the original vault geometry, with the vaults shown in context. After these three-part studies, the churches’ vaulted structures, as reconstructed, are compared. Their common characteristics are taken into account in the attempt to establish, beyond the particularities of each case, the main lines, structures and typology of Early Byzantine vault construction in western Asia Minor.

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Chapter 3 The Vaults of St. John the Theologian at Ephesos

1. Introduction The large amount of vault fragments recorded at the site of St. John the Theologian is unique among the churches of the area. Until the early 1920s, the only traces of St. John to be found above ground were the numerous, enormous, and rather enigmatic solid masses of mortar and brick, which had once belonged to the vaults of the church.236 Had half of these fragments survived until now, the graphic reconstruction of the church’s vaults would have been much easier than it actually is. Yet, unfortunately, the vast majority of them were destroyed, ironically, during the same period that marked the uncovering and rediscovery of the walls and supports: the more the plan emerged the more the vault fragments of the church were being destroyed.237

75. Ephesos, St. John the Theologian, view of vault fragment A looking south. The assumption that fragments from the western vaults, such as the ones depicted in H. Hörmann’s photographs, are indicative of all the vaults of the church is not correct. Indeed, this assumption overlooks the fact that the wide constructional and stylistic differences between the western and eastern part could betray structural differences at the level of the vaults as well. This approach can perhaps be justified by the failure to take full notice of three of the vaulted fragments that still survive on site, which, incidentally, belong to the less photographed eastern part, and are not well represented in Hörmann’s photographic records and interpretative descriptions.239 All of these fragments are significant sources of information for the graphic reconstruction of the eastern vaults, and thus cover a lacuna in our knowledge of the monument that the existing early 20th century photographic survey could not sufficiently fill.

Recent attempts to survey and reconstruct the vaults of St. John, such as the one by A. Thiel (2005), tend to be based largely on photographs of vaulted fragments in the records of H. Hörmann’s excavation, published in 1951.238 These photographs have become for many researchers the only record and source of information on the vaulted fragments of St. John. My examination of this record has concluded that it focuses on vault fragments from the west cross arm (langhaus), and gives insufficient information about the vaults of the transept and the chancel that form the east part of the church.

236 Lampakis’ photographs of the monument, taken in 1907 and now kept in the Lampakis Photographic Archive of the Christian Archaeological Museum of Athens (XAE 5967), depict the dramatic impact of these giant masses in an unexcavated landscape which, until then, had received little attention from archaeologists. Some of these fragments were again photographed by G. A. Sotiriou’s team, and published in G. A Sotiriou, (1924, p. 92). The first extensive photographic survey of many of the vaulted fragments was made by the Austrian Archaeological Institute and published in H. Hörmann (1951, pp. 92–103, Tables XX–XXVII). 237 H. Hörmann (1951, p. 92) explains the destruction of these fragments by his team as a prerequisite for the progress of the discovery of the covered ruins of the church. These ruins were buried immediately below the vault fragments, which were seen by the excavation team as obstacles. Of course, this argument sounds, today, totally unconvincing. A. Thiel (2005, p. 43) refers to these fragments, avoiding to emphasize the fact that they were destroyed by the archaeologists. 238 Andreas Thiel (2005, pp. 42–48) refers systematically to H. Hörmann’s photographs of vault fragments in his analysis of St. John’s vaulted fabric.

2. Analysis of Vault Fragments The four vault fragments that my survey was able to locate and record were found near the transept. Three meters south of it, we find Vault fragment A, which seems to derive from the springing of the pendentive on top of one of the two south piers ( fig. 75). 240 239

Indeed of the four vault fragments that still survive, only one has been studied in detail. Of the other three, all of them very important, the two have received marginal attention by H. Hörmann (1951). 240 For a brief description of this fragment, see H. Hörmann (1951, p. 102).

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76. View of vault fragment B (rotated to match the original position of the fragment).

77. View of vault fragment C looking north.

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The Vaults of St. John the Theologian at Ephesos down between the remains of the two south piers of the west bay. This fragment not only contained substantial arch remains, but also seems to have included the most extensive pendentive fragments to be found. Finally, Vault Fragment I had possibly been a vestige of the broad arch covering the west extremity of the nave. It thus constitutes one of the very few barrel vault fragments recorded in St. John.245

Vault fragment B, found next to a fig tree, 2.00m north of the north bay of the transept, probably comes from the vaults above one of the north piers of this bay (fig. 76). Vault fragment C, centrally located behind the central synthronon, is the biggest, and as the following paragraphs will show, reflects with its shape the form of one of the east pendentives that supported the central dome (fig. 77).241 Vault fragment D, though small in size, is the only surviving fragment to have received the attention it deserves by the archaeologists (fig. 78). This attention eventually led to its restoration to its original location, on top of the secondary pier at the junction between the north outer wall of the west cross arm (langhaus) and the west outer wall of the transept.242 This fragment, being the only remaining part of the aisle vaults, has a greater significance than its small size might suggest.

The information one can gather from H. Hörmann’s brief descriptions of the above fragments, with the aid of poor resolution, black and white photographs is, indeed, limited. Yet, this information can prove to be very valuable for the graphic reconstruction of the vaulted structure of the church, when seen in the light of evidence drawn from fragments that still survive. The following paragraphs will mainly concentrate on vault fragments that can serve to reconstruct the original vaulting pattern of St. John. Yet, we will also refer to vault remains that are scattered in the area north of the church, in the sites of the Baptistery and the Skeuophylakion. Unfortunately, these fragments cannot provide complete evidence for the reconstruction of the vaults of these buildings. However, they constitute important specimens of early Byzantine vaulting techniques in Asia Minor.

Information drawn from these remains can only be used in the reconstruction of the vaults of the transept. My research has not located any fragments that could possibly belong to one of the main vaults of the west cross arm. For the reconstruction of this part, a detailed study of Hörmann’s photographic survey is required. This survey contains photographs of fragments that no longer survive, most of them belonging to the west cross arm. In these photographs, we can distinguish at least four fragments whose geometry and structural fabric make it possible to identify their location and role in the original structure.243 Vault Fragment E, found broken in two large pieces, used to lie in the centre of the nave’s western bay. The place it was found suggests that it is part of the vaults above the nave’s middle north pier. The fragment seems to derive from the area of the springing (and corner merge) of two major supporting arches. The surviving mass reaches the point where the side faces of the two arches, merging in their springing, become completely detached. Vault Fragment F, with its original location allegedly being on top of the middle one of the nave’s south piers, included the part of the springing of two arches in addition to a border between the arches, which possibly surrounded a pendentive. Small Vault Fragment G included parts of the same border, together with the springing of the pendentive between them.244 Vault Fragment H, probably the most impressive and sizeable one, used to lie upside 241 R. Mainstone (1988, fig. 86, 214) has published two photographs of the fragment, without any analysis or comment. 242 H. Hörmann (1951, p. 98), who was the first to record and analyze this fragment, made the hypothesis that its original location has been in the gallery vaults. Subsequent research, cited by M. Büyükkolanci (2001, p. 63), identified the fragment as part of the aisle vaults. The fragment was eventually restored in its actual location in 1977. For an exhaustive analysis of how this fragment can serve in the graphic reconstruction of the aisle vaults see A. Thiel (2005, pp. 27–28). 243 In A. Thiel (2005, pp. 42–44), five such fragments are mentioned. 244 See H. Hörmann (1951, p. 93, Table XXI, 1 for Vault Fragment E, Table XXII, 1, 2 for Vault Fragment F, and Table XXIII for Vault Fragment G).

78. View of vault fragment D looking north.

245

See H. HÖRMANN (1951, p. 95, Table XXIV, 1 for Vault Fragment H, and Table XXV, 1, 2 for Vault Fragment I).

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Early Byzantine Vaulted Construction in the Western Coastal Plains and River Valleys of Asia Minor

79. Detail of vault fragment A, showing remains of broad arch consisting of two arch-rings. Vault Fragment A

that their inner rings must have merged at this point. Indeed, taking into account the diameter of the arches (approximately 12.40m), which can be deduced from the plan, as well as the thickness of their rings (approximately 0.35m each), measured on the fragment, we find that the merging between the inner rings must have taken place 2.00 meters above their springing. Above this level, the arches separated entirely, with the pendentive springing between them.248 Because of this merging, the faces of both broad arches must have converged to a single point, corresponding to a pier corner. This agrees with the profile of the piers of the south bay of the transept, in which there are no re-entrant angles.

This fragment allows us to explore the structural fabric of one of the pendentives of the south bay of the transept, together with its supporting arches and solid brick backing.246 Observing the brick masonry mass, the first elements I distinguished were two pairs of 10 – 15 brick courses laid radially. These begin to form two broad arches (or barrel-vaults), each consisting of two concentric rings of radial bricks (fig. 79). One of the arches is now buried in debris. The buried arch seems to conserve both its superimposed rings, whereas the exposed arch has lost its inner ring, which formed its intrados.247 These broad arches seem to meet at right angles. Drawing our attention to the corner where they converge, we find

248

A similar convergence in the arches that carry a dome (and thus an elevated springing of the pendentives) is noted in a series of vaulted basilicas whose primary piers lack re-entrant angles. Here are some characteristic cases, each one followed by the distance between the springing of the supporting arches and the level of the springing of the pendentives (P. S. L.), of course, proportional to the arches’ radius and thickness: Hagia Sophia, Constantinople (dome diameter: 32m) – P. S. L.: 7.5m, St. Eirene, Constantinople (dome diameter: 16m) – P. S. L.: 5 m, Church at Derea÷zƭ, Lycia (dome diameter: 9m) – P. S. L.: 2.5m. What distinguishes these cases from the case of the dome in St. John’s transept, explaining the relatively lower pendentive springing in the latter, is the fact that in all of their supporting arches both inner and outer rings are exposed, whereas, in St. John only the inner ring was visible from the interior of the church.

246 The fall of this fragment resulted in part of it now being with its originally horizontal joints upright. The other part of the fragment has been detached across a vertical joint and is now found lying on the ground, and buried in overgrowth. The following description refers to the complete fragment in its original orientation in relation to the horizontal axis. 247 Indeed, the only visible courses of the buried arch clearly show that the latter included two arch rings. The exposed arch must have also included two rings of radial bricks. The rough surface of the intrados of this arch betrays that its external ring, insufficiently bonded to the rest of the structure was detached from it after the collapse.

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80. Detail of vault fragment A, showing remains of supporting arch, and pendentive. The pendentive is flanked by two borders consisting of three brick courses. Fragment A must have originated from a level just above the point where the inner rings of the arches merged. Examining its part which is presently nearer to the ground, we are confronted with substantial remains of a pendentive (fig. 80). The lowest point of the pendentive seems to coincide with the point where the inner rings of the supporting arches become independent, 2.00 m above their springing line. The horizontal courses of the pendentive seem to be surrounded by a border consisting of three pitched brick courses. These courses lean against the chamfered, sloping faces of the outer rings of the broad arches, and follow their semi-circular course.249 As it will be shown, this detail is crucial for the reconstruction of the vault to which this particular fragment belonged. In the wedge-shaped area enclosed within this border, the construction changes, with the main mass of the pendentive consisting of bricks laid in horizontal, circumferential courses with a gradually increasing inclination from the horizontal. Eleven such courses survive. The examination of the top side of the fragment shows that this pendentive was in fact two bricks thick, with a second shell lying behind the extrados of the supporting arches and serving to anchor the pendentive into the vault core (fig. 81).

81. Vault fragment A, view from the top. This view reveals two essential elements: the double shell of the pendentives and the inner ring of one of the supporting arches.

249 This intermediate border of bricks surrounding a pendentive and separating it from the supporting arches has been named “charfrein” in A. Choisy (1883, p. 92).

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Early Byzantine Vaulted Construction in the Western Coastal Plains and River Valleys of Asia Minor

82. Vault fragment A. Reconstructed axonometric view from above. The extant remains are demarcated by a grey outline (drawing by Nikolaos Karydis, 2008). of bricks out of line with the general grid. These irregularities allow each of the courses of the backing to fill triangular spaces and thus to adapt to the irregular plan of the vault core.

The broad arches and the pendentive are constructed of large, thin bricks, of three distinct types. There are big, rectangular bricks measuring 35x50x4.5cm (type A), medium sized, square bricks measuring 34cm square by 4.5 cm (type B), and, finally, half – size bricks measuring 17x34x4.5 cm (type C). This variety of sizes is required to make the bricks interlock, ensuring a neat bond within each element (arch ring, pendentive shell), but also an occasional, but not systematic, bond between the elements themselves. Thus, for instance, there are many cases where some of the big rectangular bricks (type A) of one of the arch rings extend into the other ring, thus ensuring a slight bond between the two masses. This minimal bond, as we now see, has not been enough to prevent the detachment between the two rings during collapse, and hence the subsequent disappearance of the intrados of one of the arches.

Fragment A can offer important information about the vaults that once covered the transept of St. John. Indeed, the completeness of the fragment, including both broad arches and pendentive, allows us to reconstruct the fabric of the vaults down to considerable detail (figs. 82 and 83). The particular way in which the pendentive engages with the broad arches offers essential evidence for reconstructing the form of the dome the pendentives carried. However, the examination of this fragment is compelled to leave us with many uncertainties as well: with the intrados of the broad arches either missing or buried we cannot easily draw conclusions about its original appearance. Furthermore, our reconstruction of the merging of the supporting arches in the springing of the vault has, until now, been largely hypothetical. Further proof is required to understand the precise form of the feet of the vaults.

Observing the surface of the vault, we realize that its bricks seem to be quite regular in size and shape. This regularity vanishes in the backing of the vault. In the unexposed areas of the core, broken and irregularly shaped bricks frequently occur, in combination with a liberal use of mortar between them, and with some rows

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The Vaults of St. John the Theologian at Ephesos

83. Vault fragment A. Reconstructed axonometric view from below. The extant remains are drawn in detail, reconstructed elements in dashed outline (drawing by Nikolaos Karydis, 2008).

Vault Fragment B The examination of vault fragment B confirms many parts of the partial reconstruction attempted in fragment A (fig. 84).250 Its similarities with fragment A seem to indicate the design symmetry between the north vault of the transept and its south counterpart. In it, we are confronted with a vault segment that belongs to the area immediately lower than the one included in fragment A: here, the springing of the pendentive has completely survived, as well as both rings of the two supporting arches, the merging of which in the springing, although still absent, is now more obvious (figs. 85, 87). The survival of these elements gives us the opportunity to study both the brickwork of the intrados of the supporting arches and its finish (see fig. 76). It now seems certain that the inner rings of the broad arches were built with their bricks laid in neat common bond, with their vertical joints staggered. The use of three sizes of bricks, and the irregularities of the solid brick backing are attested here as well.

84. Vault fragment B, view from the west. Detail of the convergence of two broad arches, showing the springing of a pendentive between them.

250 Falling on the ground, this vault fragment has been rotated by 90°. It is better observed from the South, from the ditch created by the excavators to reach the floor level of the church.

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Early Byzantine Vaulted Construction in the Western Coastal Plains and River Valleys of Asia Minor

85. Vault fragment B. Reconstructed axonometric view from above. The visible remains are surrounded by a grey outline (drawing by Nikolaos Karydis, 2008).

A small patch of non-figural mosaic covers the eight lowest courses of one of the broad arches, at the point where it meets the soil. The mosaic is composed of white and dark cobalt blue tesserae. This seems to be the only surviving mosaic from St. John (fig. 86).251

northernmost arches of the transept. However, this conclusion can only be confirmed through the examination of vault fragment C, which includes the only surviving pieces from the central arches.

The good preservation of fragment B reveals a particular characteristic, which we could not have suspected in the case of fragment A: in one of the arches, the inner ring is markedly thicker than the outer one, and thicker than each of the rings of the neighbouring arch. This ring has a thickness of 50cm, and consists largely of rectangular bricks measuring 35x50cm. Thus, the complete thickness of one arch is around 85cm, whereas the arch close to it, consisting of two identical, superimposed rings, has a thickness of only 70 cm. This asymmetry is likely to reflect the different role of the two arches. It is quite possible that the arches linked with the central nucleus were given a greater thickness than the southernmost and 251 G. A. Sotiriou (1924, p. 109) was the first to find traces of St. John’s mosaics. Unfortunately, these fragments do not appear to have been photographed and published by the author. The mosaic I found is likely to be the one first observed, and briefly described (but not photographed) in H. Hörmann (1951, p. 98) and considered lost in A. Thiel (2005, pp. 42–44, fn. 283).

86. Vault fragment B. Remains of mosaic with white and blue-green tesserae.

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The Vaults of St. John the Theologian at Ephesos

87. Vault fragment B. Reconstructed axonometric view from below. The visible remains are drawn in detail, reconstructed surroundings with a dashed outline (drawing by Nikolaos Karydis, 2008).

88. Vault fragment C. View from the southeast, showing remains of supporting arches (with double arch-rings) and vault core.

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Early Byzantine Vaulted Construction in the Western Coastal Plains and River Valleys of Asia Minor

89. Vault fragment C. Reconstructed axonometric view corresponding to the view of figure 88. Only the visible remains are drawn in detail. Reconstructed parts are shown in dashed outline (drawing by Nikolaos Karydis, 2008). Vault Fragment C their faces were independent. The same detail demonstrates that, here, it must have been the outer arch rings, as opposed to the inner ones, that intersected and merged in their springing.

Observing the gigantic brick mass fallen behind the synthronon east of the crossing, one is able to distinguish parts of supporting arches and their solid brick backing. Comparison with the previous two fragments easily identifies this piece as yet another vault segment from the area of the foot of the pendentives.

We can draw two conclusions from this detail. Firstly, the total independence between the inner rings of the supporting arches suggests that these arch-rings were carried by pilasters projecting from a main pier. This tallies with the shape of the four piers surrounding the bay of the crossing and helps to explain the re-entrant angle in their profiles (fig. 7). Secondly, we realize that, in the crossing, the greatest part of the faces of the supporting arches, including the faces of the outer arch rings, must have been visible from the interior of the church.

The southeast corner of the fragment offers evidence for broad arches constructed with two concentric rings of radial bricks (fig. 88). The fact that both of the arches converging in this corner are extremely dilapidated allows one to observe the fabric of the solid brick backing, originally behind the pendentive and arch shell, now partly revealed. This backing seems to have consisted of horizontal courses of brick, which butted against the vault shell. The curvature of the face of this core, partly semi-cylindrical and partly spherical, betrays the form of this shell (fig. 89).

The fact that the arches surrounding the bay of the crossing had their structural mass almost entirely exposed reveals a lot about the connection between the supporting arches and the pendentive between them. The pendentives of the crossing must have lied on top of the extrados of the supporting arches, unlike the previous ones we examined, which lay against the sloping face of

In this particular vault fragment, the detail of the merging between the converging broad arches is different from the one observed in the other fragments. Here, the inner rings of the arches were tangential one to the other. Indeed, a detail shown as “K” in figure 89, proves that, in this case,

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The Vaults of St. John the Theologian at Ephesos

90. Vault fragment C, view from the northwest. Note the intersection between pier and broad arch on the left part of the figure.

91. Hypothetical reconstructed axonometric view of vault fragment C and its immediate surroundings from below. Note the barrel vaults covering the gallery, the broad arches crowning a hypothetical fenestrated tympanon, and, on the right, a detail of the central dome (drawing by Nikolaos Karydis, 2008).

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Early Byzantine Vaulted Construction in the Western Coastal Plains and River Valleys of Asia Minor these arches (see fig. 102).252 As I suggested in the examination of fragment A, the particular nature of this connection is crucial for the reconstruction of the central part of the spherical vault. Indeed, a comparative study of such details is likely to betray a difference in type and geometrical form between the vaults of the lateral and the central bays of the transept.

This composite structure brings to mind the domical groin vaults of the narthex of St. Eirene at Constantinople.255

The examination of the present northwest corner of fragment C also confirms that the latter belonged to one of the piers of the crossing (fig. 90). In this corner, we can clearly distinguish the intersection between pier and broad arch. The width of the pier exceeds the soffit-width of the arch. The only piers to be substantially wider than broad arches they carry are the ones that surround the crossing. This is deduced from the fact that the soffit width of the broad arches interconnecting the central to the smaller, peripheral piers could not have exceeded the width of the smaller piers. Therefore, the fragment should probably be identified as part of a central pier. But let us return to the intersection between arch and pier, as observed in fragment C. This detail offers us the only available evidence for the form of the upper parts of the central piers. Indeed, in order for this intersection to exist, the piers ought to have risen at least 4 meters higher than the springing of the arches, behind the pendentives, forming a square dome-base visible from the exterior (fig. 91). Similar dome bases had appeared in previous reconstructions without adequate archaeological evidence.253

92. Vault fragment D, view from the southwest.

Vault Fragment D The identification of vault Fragment D as part of the aisle vaults makes it the solitary surviving fragment of the secondary vaults of St. John. The multiplicity of vaulted surfaces forming the complicated shape of this fragment is indicative of the complexity of the vaulting which once covered the aisles (fig. 92). Observing the fragment closely, it is possible to distinguish the remains of two arches: arch A, parallel to the main axis of the aisle, and arch B, perpendicular to the first. The location of arch A, and its junction with a spur wall, both suggest that it covered one of the windows piercing the north wall.254 Arch B, on the other hand, crossed the aisle interconnecting two piers (fig. 93). Between the two arch fragments, we distinguished a groin marking the line of intersection between barrel vaults. This area of the fragment consists of two horizontal zones: the lower part is made of some 20 horizontal oversailing brick courses, while the upper one is built with bricks pitched on edge. 252 Indeed, in both fragments A and B, the pendentive shell covered the face of the outer ring of the arches lying against it. 253 Both H. Hörmann and A. Thiel have reconstructed the church with similar dome-bases over the crossing, without however justifying their design with information from archaeological remains. A. Thiel (2005, p. 48), in particular, suggested that the dome base rose 7m above the roofs of the galleries. 254 The visible remains of this arch seem to consist of 21 courses of halfsize bricks (with face dimensions: 18x4.5cm) laid in a radial way. See H. Hörmann (1951, p. 99).

93. Vault fragment D. Reconstructed axonometric, view from below. Extant remains are marked by a grey outline (drawing by Nikolaos Karydis, 2008). 255

80

See W. S. George (1913), p. 37.

The Vaults of St. John the Theologian at Ephesos Vault Fragments Recorded in the Photographic Survey of 1951

The requirements that necessitated the use of such a peculiar pendentive structure in the west cross arm must have been related to the oblong shape of its bays. A direct result of such a bay shape is that the apexes of the broad, semi-circular arches in its short sides are at a lower level than the apexes of the arches in the long sides (fig. 94). In an oblong bay, such as the one of figure 94 it is not possible to form a horizontal ring directly over the apexes of all the arches, as the one required to construct a hemispherical, shallow, or semi-ellipsoid dome directly above the arches. In similar cases, the builders would deal with such a problem by modifying the tracing of the short arches, making them slightly elliptical, or, possibly elevating their springing, with all the irregularities that this modification would entail.260 But, in St. John, the nave’s pendentive remains betray the use of a different solution. Here, the compensation for the height difference between longitudinal and transverse broad arches is to be found in the structure of the pendentives rather than in the tracing of the arches. Indeed, my drawings prove that the use of a thick border (9 pitched brick courses) over the short arch, combined with the use of a thinner border (3 pitched brick courses) over the long arch, would effectively serve to make up for the height difference of the arches. Yet, as it will be shown, this is not the sole function of the pendentive borders.

Vault fragments A–D provide considerable information about the form of the original vaults. And yet, our knowledge of these vaults is far from being complete. Indeed, whereas some parts of the vaults over the transept and the chancel can be reconstructed, only a fraction of the vaults over the western half of the church has been identified. This important lacuna can only be partly filled, with the aid of H. Hörmann’s and J. Keil’s photographic survey. Even though these photographs do not allow a close examination of the vault fragments, they can serve to establish to what extent the nave vaults are different from the ones covering transept and chancel. Examining the photographs of fragments E and F [see H. Hörmann (1951), tables XX, 1, and XXI, 1 respectively], we cannot find any structural differences between the broad arches of the west part and the ones of the transept and chancel.256 Fragments G and H [see H. Hörmann, (1951), tables XXIII, 2, and XXIV, 1 respectively], on the other hand, seem to suggest that the pendentives of the west cross arm, differed structurally from the pendentives of the transept.257 The first difference is found in the thickness of the borders surrounding the pendentives, uniform in the transept, varying in the west cross arm. Yet, the most important difference regards the structure of the pendentive itself (see fig. 113). As the photograph of the impressive vault fragment H clearly demonstrates, the pendentives of the two west bays were formed with bricks laid in arched, concentric courses.258 After 15 arched courses, there are traces of a segmental arch with radiating bricks, connecting two pendentive borders of unequal thickness, and crowning the lowest, wedge-shaped portion of the pendentive.259 This description is indicative of an unconventional pendentive structure, quite unlike the one observed in fragments A and B. The repetition of the above structural form in more than two distinct fragments found lying in the west bays suggests it had been systematically used in the latter’s major vaults.

The structure of the dissimilar borders appears to be a device aimed at forming a perfectly horizontal circular ring, serving as a base for either a hemispherical or a shallow dome. Indeed, this use of dissimilar borders compensates not only for the different height of the arches, but also for rectangular shape of the bays. Figure 95 shows that the differential protrusion of pendentive borders causes the departure from the rectangular plan of the arches, and the creation of an arched border with a square plan. The latter would allow the building of either a dome on pendentives or a pendentive dome, similar to the ones that we find in Early Byzantine monuments, over square bays. H. Hörmann has also recorded two fragments (J and K) that derive from the immediate surroundings of the gallery vaults and thus offer information about a part of the structure that has now entirely disappeared. Although these fragments do not include any vaulted parts, they deserve to be included here as they can offer valuable evidence for the reconstruction of the vaults that stood in their immediate vicinity.

Both the use of arched courses and borders of different thickness in the pendentives of the western part deviate from the standard practice, exhibited in the remains of the transept. This is yet another instance of the use in the nave of different construction methods from the ones used in the lateral bays of the transept and in the chancel. This structural difference is one more indication for a change in phases as we move from the transept to the west bays of the church.

Fragment J seems to have been a part of the external wall of the gallery.261 It probably comes from the secondary 260

An instance of the use of such a method to deal with the problem of the oblong bay is noted in St. Eirene, at Constantinople. In the rectangular west bay of this church the short sides are covered by elliptical arches. See U. Peschlow (1977, table 5), W. George (1913, p. 41, fig. 22), and C. Mango (1978, p. 87, fig. 118). This solution was not used in St. John, where the arches were semicircular. The reconstruction by H. Hörmann (1951, table LXIX) suggests that the builders tried to respond to the unequal height of arches in the bays of the nave, by slightly elevating the springing of the narrow arches. This, however, contradicts the evidence of fragments E and F. 261 See H. Hörmann (1951, p. 100, table XXVII, 3).

256 Like their eastern counterparts, the west broad arches were built with radial courses of brick, which merge in a similar way close to the springing, to ensure the transition from the vaults to the rectangular pier profile. Cf. H. Hörmann (1951, pp. 92–93, tables XXI, and XXII). 257 Cf. H. Hörmann (1951, p. 93, fig. 14 ii, tables XXIII, XXIIV). A. Thiel (2005, pp. 47–48), arrives at the same conclusion. 258 According to H. Hörmann (1951, p. 94), 7 such courses survived in fragment G and 15 of them in fragment H. 259 See H. Hörmann (1951, pp. 94–95, Table XXIV, 1).

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94. Axonometric of the four arches surrounding the west bay of the church. Notice the height difference between the longitudinal and the transverse arches (drawing by Nikolaos Karydis, 2009).

95. Ephesos, St. John the Theologian, Axonometric diagram of the four arches of figure 94 after the addition of pendentive borders. The latter make up for the height difference observed in the previous figure (drawing by Nikolaos Karydis, 2009).

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97. Ephesos, St. John the Theologian, Skeuophylakion, entrance hall. Note the remains of a semidome over the apse at the end of the hall.

96. Ephesos, St. John the Theologian, view of the narrow corridor between the transept and the baptistery complex, showing a barrel vault consisting of two rings of bricks set radially.

Vault Fragments from the Baptistery and the Skeuophylakion

pier that marks the junction between the south gallery of the west cross arm and the southwest gallery of the transept.262 This fragment seems to preserve traces of two perpendicular pier faces, made essentially of brick masonry. Parts of blind arches occur in both faces and a string course of squared stone blocks marks the bottom of the fragment. We do not notice any trace of a barrel vault springing anywhere lower than the crown of these arches: this observation will prove to be essential for the reconstruction of the gallery vaults of St. John.

The area north of the church, including a Baptistery and a Skeuophylakion which were more recently – and carefully – excavated than the main church, preserves a series of vault remains. Among them, we find a well preserved barrel vault (fig. 96). The latter covers the narrow corridor between the north cross arm of the main church and the western anteroom of the baptistery. The shell of this semi-cylindrical vault is composite: its springings are made of special, large bricks (50cm square), which are set radially and run through the entire thickness of the vault; the crown, however, is composed of two rings of bricks, the inner consisting of standardsize bricks (35cm square) and the outer made of half-size bricks, with faces 17.5 cm long. The excessive overall thickness (50cm), seemingly unusual for a vault spanning only 1.50m, is something normal for a barrel vault which was obviously part of a buttress counteracting the thrusts of the major vaults (see plan of fig. 7). The solitary surviving semidome remains in St. John belong to the apsed hall of the Skeuophylakion. These remains consist of merely seven horizontal oversailing courses of brick squashed between the south wall and the arch over the west entrance. These courses obviously belonged to the springing of a semidome. Their interruption by the arch suggests that the springing line of the semidome was located below the apex of the arch supporting it (fig. 97).

Further evidence for the form of the gallery vaults may be found in fragment K. This fragment probably comes from the summit of the southeast major pier of the west cross arm.263 This is the solitary pier fragment from the gallery level, and the only proof for the fact that the upper part of the piers was made of brick. The structural role of the marble cornice surviving in the topmost part of the fragment would have been to provide a firm seating for the major supporting arches.264 The sculptural treatment of the members of the cornice is not uniform: those members that had been exposed to the nave projected outwards and had a moulded profile, whereas the rear members seem to have been flush with the faces of the pier. This seems to suggest that the rear part of the pier, which originally faced the gallery, was not exposed but had originally been covered by the structure of the gallery vaults.

An interesting vault fragment is found inside the southeast ancillary chamber of the Baptistery (fig. 98). The fragment, located at the southeast corner of the chamber, consists of bricks pitched on edge. The latter are laid parallel to the two side-walls and interlock along the diagonal, where a blunt ridge starts to be formed. Both this ridge and the triangular plan of the room suggest that, here, we are dealing with what could be designated as a semi-domical vault. A way to get a notion of how the original vault might have looked like is to

262

See A. Thiel (2005, p. 31). The fragment has received a lot of attention. Excellent descriptions, drawings and photographs occur in H. Hörmann (1951, pp. 94–95, fig. 14, 1, table XXVI, 1 and 2). 264 L. Butler (1992, p. 65) described in detail the dressing and profile of the marble blocks of this cornice, as well as their firm connection with metal cramps. Even though his analysis is in many points thorough and detailed, L. Butler misidentifies the origins of the fragment, claiming that it comes “from the lower cornice of the southeast pier of the nave”. Still, the pier masonry below the cornice is not made of ashlar blocks but of brickwork, something that indicates the fragment’s provenance from the level of the gallery. 263

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98. Ephesos, St. John the Theologian, Baptistery, southeast ancillary chamber, remains of domical groin vault. imagine a typical Byzantine domical groin vault of which the half of the structure beyond one of the diagonals has been removed.

- There must have been a structural difference between the spherical vaults over the cross arms, and the one over the crossing. Their main difference is found in the construction of their springing: the shell of the central vault rested on the extrados of the supporting arches, while the shell of vaults over the cross arms lay against the face of the arches (compare figs 85 and 89). - Earlier reconstructions showing the rectangular west bays covered by vaults built on an elliptical plan are incorrect. The use of a border with varying thickness between the supporting arches and the pendentives in these bays, made it possible to construct a spherical vault on a circular plan (see figs 94, 95). - There is a structural difference between the pendentives of the west cross arm, made with bricks laid in arched courses, and the ones of the transept, made with bricks laid in circumferential courses (see figs 79–83).

These scattered fragments seem to have belonged to types of vaults that have not been encountered elsewhere in the remains of St. John. The following chapters will show that fragments of groin vaults, and semidomes are not often found in churches of west Asia Minor. In this respect, they are tremendously important for our research, as they complete our understanding of early Byzantine vaulting techniques in the region. Conclusions from the Examination of Vault Fragments Vault fragments yield important information about the original structure of the vaults of St. John, giving crucial evidence for the reconstruction of the church. Fragments A and B, both belonging to the transept vaults, are analysed here for the first time. This original analysis makes structural comparisons between the vaults of the west bays and the vaults of the transept possible for the first time. Our main conclusions from this comparison, which completes the first stage of our research into the vault structure of St. John, are the following: - Both the main architectural space of the church, and its central structure were compartmentalized. They consisted of a number of centralized cells surmounted by spherical vaults, which were carried by broad arches.

This survey of vault remains has been an important step towards the reconstruction of the original structure of the vaults of the church. Yet, there remain to be studied evidence of potential relevance to the work of reconstruction of a quite different kind: vault remains should be re-examined in the light of information drawn from literary sources and manuscripts. The careful examination of documentary evidence allows us to approach the problem of reconstruction in a multi-faceted manner, synthesizing information from the archaeological remains described above, and evidence from written word.

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3. Documentary Evidence

shallow dome, most of the surface elements (such as a mosaic’s tesserae) depend almost entirely on their adhesion with the mortar bed. This adverse characteristic, combined with structural decay and earthquake action, could have made mosaic fall a frequent phenomenon, as G. Tornikes complains.

The survival of written testimonies, referring more or less directly to the vaults of St. John is something exceptional among the early Byzantine churches of west Asia Minor. Even in the case of St. Mary at Ephesos, so closely linked with the Ecumenical Council of 431 A.D., no hints about architectural form are to be found in historic sources. The existence of numerous written records referring to St. John can be attributed to the high status of this church, its links with imperial initiative, and its role as a key monument of one of the most important and lasting cities of the Byzantine Empire.

Even though Georgios Tornikes refers only indirectly to the vaults of St. John and does not give a proper description, his account remains a reliable reference on this subject. Due to the facts that this 12th century testimony uses the term sfairomata (used by Procopius, in the 6th century, to describe saucer domes) and reports a failure, which is more likely to occur in such structures, it could be, perhaps, considered a small indication for the existence of shallow domes in St. John. After all, Ibn Battuta’s claim that the domes of the church were of varying sizes may well indicate the co-existence, side by side, of domes on pendentives and pendentive domes. However, in order to ascertain the use of this specific vault structure, more explicit evidence, or, at least, further indications are required. Such indications can be found in the writings of Procopius of Caesarea, which are contemporary to the Justinianic building phase of St. John.

Ibn Battuta The traveller Ibn Battuta has left us with one of the last historic accounts on St. John. Written in the early 14th century, probably less than a century before the church was destroyed, Ibn Battuta’s description is a puzzle for anyone who tries to compare it to the archaeological remains.265 The traveller mentions that the church, when he visited it, had no less than 11 domes of varying sizes. This statement has received various interpretations by scholars. For instance, it led H. Hörmann to reconstruct domes not only above the six main bays, but also above each of the five bays of the gallery over the narthex.266 Unfortunately, the number given by Ibn Battuta cannot be considered as useful evidence for the monument’s reconstruction. Firstly, due to the author’s failure to give any clues about the location of domes, and, secondly, because his text includes a number of exaggerated statements which seem to compromise its credibility. Indeed, Ibn Battuta also refers to the existence in St. John of basins with fountains under each dome, a characteristic more typical of Moorish Andalusia and Morocco than Byzantine Ephesos. Nevertheless, this rare historic account constitutes important evidence for the repetitive use of the dome – either shallow or hemispherical – as modular element in St. John’s structure.

Procopius We should be grateful to Procopius for his account of the rebuilding of St. John by Justinian, written in the middle of the 6th century. Indeed, this seems to be the only surviving contemporary chronicle referring to church building in early Byzantine Asia Minor. Unfortunately, this rare report, although rich in information about St. John’s construction’s phases, does not say a word about the church’s original form.268 Procopius’ only hint in this respect is that, this church, after Justinian’s “demolitions”, and “modifications” of the previous “shorter” building, “resembled very closely in all respects, and is a rival to, the shrine which he dedicated to all the Apostles in the imperial city.”269 The Justinianic phase of the church of the Holy Apostles at Constantinople, a church completed around 550 and demolished in 1469, is therefore a key point of reference for the present research.270 Given the resemblance between the two churches, a series of surviving

Georgios Tornikes The earliest written report on St. John’s domes that has survived is the one by Georgios Tornikes, Metropolitan of Ephesos.267 Written in the 12th century, this report refers to the domes of St. John as ıijĮȚȡȫȝĮIJĮ (sfairomata), literally “spherical surfaces”, a term that could either describe hemispherical or shallow domes. Tornikes insists on the bad condition of the domes, which causes parts of their mosaic revetment to fall in the nave and, occasionally, on the heads of the worshipers. Such a detachment would have been more likely for a shallow dome rather than for a hemispherical one. Indeed, in a

268

See Introduction, I, 3. According to Procopius, “Justinian (…) by demolishing [part of an earlier church], modified the size and beauty [of the church] to such an extent that (…) it resembles very closely (…) the shrine which he dedicated to all the Apostles”. See Procopius (V. i. 6). H. Plommer (1962, p. 119) has criticized H. Hörmann for not giving to the Holy Apostles the importance they deserve as a parallel of St. John. 270 Procopius’ claim should be given much credit since it comes from a writer contemporary to the inauguration of both buildings, and in close contact with the emperor who commissioned them. A subsequent testimony seems to confirm the account of Procopius. Indeed, according to George Codinus (1839-1843 cited in G. A. Sotiriou, 1924, p. 125), a 15th century document that probably reproduces middle Byzantine testimonies, “…the Empress Theodora [Justinian’s wife] took both the shape and plan of the church of the Holy Apostles from the church of St. John the Theologian at Ephesos”. 269

265 For Ibn Battuta’s description, see M. Büyükkolanci (2001, p. 39), and A. Thiel (2005, p. 108). 266 See H. Hörmann (1951, p. 160). For a refutation of the argument championing the existence of domes over the west gallery, see A. Thiel (2005, p. 25). 267 This report, cited by G. A. Sotiriou, (1924, p. 128) is included in a letter addressed by the Metropolitan to Theodoros Pantehin.

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Early Byzantine Vaulted Construction in the Western Coastal Plains and River Valleys of Asia Minor hemispherical ones.277 By the time of Constantine of Rhodes, the shallow domes mentioned by Procopius must have been subsequently remodelled. This remodelling could have involved the replacement of shallow by hemispherical domes, in the same way as in Hagia Sophia during the 6th century. Therefore, the building that 6th century St. John resembled according to Procopius can only be visualised through its 6th century description by the same author, a description that indicates the use of shallow domes on pendentives in all the bays of the church.

descriptions of the Holy Apostles, which refer extensively to the vaults of the church, have the potential to give us a significant insight into the nature of the missing vaults of St. John at Ephesos. There are three reliable historical descriptions that tell us about the form of the Holy Apostles: one by Procopius, contemporary to the church’s building; a 10th century source, in the form of a poetic ekphrasis, by Constantine of Rhodes; and another ekphrasis written in the 12th century by Nikolaos Mesaritis. According to Procopius, the spherical vault that covered the crossing of the Holy Apostles was built in a similar way to the central vault of Hagia Sophia.271 This description, whose exact date has not yet been ascertained,272 quite possibly refers to Hagia Sophia’s short-lived first dome, which collapsed in 558, twenty years after its construction.273 This was a pendentive dome, and not a hemispherical dome on pendentives such as the present one.274 It is this shallow dome with a dense sequence of windows in its base, and resting on pendentives, which resembled the dome over the crossing of the Holy Apostles. This church also had four projecting arms, which, according to Procopius, were surmounted by shallow domes on pendentives, without windows in their base.275 Therefore, Procopius, describing the Holy Apostles gives us an outline of a cruciform building, with all its five bays covered by shallow domes on pendentives.

Procopius’ statement concerning the similarity between St. John and the Holy Apostles does not automatically suggest that the vaults of the two monuments were identical. Indeed, it may be argued that the same statement would be just as valid in case some or all of the vaults of St. John were hemispherical domes on pendentives, a kind of vault just similar but not identical to the pendentive domes of the Holy Apostles. It may well be that Procopius did not consider the difference between a hemispherical dome and a shallow one important enough. However, if this was the case, then it is difficult to explain where the 6th century author found the similarity between the two monuments. Their plans were quite different. The Ephesian monument had six major vaulted bays whereas the Constantinopolitan one had only five. Unlike the Holy Apostles, St. John had a considerably elongated plan. Its accentuated longitudinal axis must have given the Ephesian church a dynamic directional impact absent from the church of the Holy Apostles, with its quasi-centralised plan. These differences suggest that, if there was a resemblance between the two buildings, this resemblance must have concerned either elements of their elevation or the design of specific bays, seen from the interior. In both these areas, the appreciation of the form of the vaulting would probably have been crucial in perceiving possible resemblances. Therefore, it is likely that one of the elements that made St. John and the Holy Apostles similar was the use of vaulting in the two monuments. And, as the shallow domes on pendentives were among the dominant characteristics of the Holy Apostles, it is likely that the same vault form was used in St. John as well. Still, the extent of this use remains to be established.

This 6th century description seems to contradict the later, 10th century poem by Constantine of Rhodes. This Middle Byzantine document rather alludes to hemispherical domes on pendentives, as opposed to pendentive domes.276 But, the contradiction between the two testimonies may be explained if we take into account the reconstruction work carried out in the Holy Apostles in the 9th century, which could have resulted in the replacement of the shallow domes of Procopius’ time by

271 According to Procopius, I. iv. 15, the vault that covered the crossing of the Holy Apostles “…is built in a way similar to the Church of Sophia [i.e. Hagia Sophia, in Constantinople], except that it is inferior to it in size”. 272 For a discussion on the date of Procopius’ de Aedificiis, based on the writer’s reference to the imminent completion of the Sangarius bridge, and a late dating of this book to 560 / 561 AD, see M. Whitby (1985, pp. 141–147). Cyril Mango (1992, pp. 42–43), on the other hand, champions an earlier dating, three or four years before the collapse of the first dome of the “Great Church”. 273 Indeed, there is a consensus that “the dome Procopius described was the first one”. See R. Taylor (1996, p. 69). 274 Indeed, according to at least two other contemporary testimonies, the ones of Agathias, and Malalas, both discussed in R. Mainstone (1988, p. 90), the first dome of Hagia Sophia had a shallower profile than the one that replaced it, with a height 20 feet inferior to the height of the reconstructed dome. 275 According to Procopius (I. iv. 17) the domes over the cross arms of the church resembled the central one, with the only difference being that there were no windows in their bases. 276 According to this poem, cited in R. Taylor (1996, p. 77), the architect of the Holy Apostles “…wove one arch to its mate, wove cylinder to cylinder; he tied pier to pier, one to another; and he bound each sphere, cut in half like a hill, to another spherical construction”. A shallow dome, often generated from the same spherical surface as its pendentives, can hardly match the description of a sphere cut in half.

According to Procopius, the resemblance of St. John with the Holy Apostles was an attribute that resulted from Justinian’s remodelling of the Ephesian church. If this remodelling introduced shallow domes similar to the ones of the Holy Apostles, then these domes must have surely surmounted the bays of the west cross arm, the part that Justinian added to the church, as the imperial monograms in the capitals testify (fig. 99).278 If the older parts 277

See R. Krautheimer (1986, pp. 242, 407). A. Thiel (2005, p. 45–48) also claims that the poem of Constantine of Rhodes refers to the state of the building after a 9th century remodeling that involved the modification of the vaults. 278 Procopius’ account seems to suggest that St. John’s building phase prior to Justinian was not similar to the Holy Apostles. Indeed, Procopius (V. i. 6) clearly claims that “Justinian (…) modified the size

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99. Ephesos, St. John the Theologian, view of the south colonnade of the nave. The imperial monograms of Justinian and Theodora can be distinguished on the faces of the Ionic impost block capitals. Conclusions from the Examination of Literary Sources

(transept and chancel) were also covered by shallow domes, there would, perhaps, have been fewer grounds for Procopius associating Justinian’s intervention at Ephesos with the similarity between St. John and the Holy Apostles.

Our overview of 6th century testimonies and later documents seems to indicate that the forms of vaulting that were used in the Justinianic phase of St. John had a lot in common with early 6th century Constantinopolitan vaulting practices. The main point connecting the two seems to be the use of the shallow dome on pendentives over some of the major bays. According to our reading of Procopius, the repeatedly attested similarity between St. John at Ephesos and the Holy Apostles in their Justinianic phase may reflect a common use of such shallow domes in both monuments. If this is true, then the Justinianic St. John becomes part of a group of monuments, including Hagia Sophia, and the Holy Apostles, in which the ambitious use of the shallow dome over wide spans, later to be abandoned by Byzantine builders, had been a central characteristic.

According to this interpretation, the description of Procopius seems to indicate that the western bays of St. John were covered by shallow domes. This evidence however, relying to only one of the possible interpretations of the words “close resemblance”, used by Procopius, a person who was neither an architect or a builder, is far from being conclusive. It constitutes, however, another indication for the use of shallow domes in St. John. This form of vaulting, typical of Justinianic churches of Constantinople, might have been an architectural element used by the Emperor to place his mark on the church – mausoleum of St. John in Ephesos, one of his Empire’s most prominently located and symbolic monuments.

Yet, the various uncertainties surrounding the above examination prevent us from proving the use of shallow domes in St. John. The accounts examined are none the less useful in another way: by indicating the possible existence of shallow domes, or the use of different vaulting patterns throughout the church, they warn the researcher against the use of stereotypical reconstruction solutions. Such solutions often exclude the possibility of an irregular vaulting pattern marked by a structural difference between the vaults of the transept and the ones

and beauty [of the church] to such an extent that (…) it resembles very closely (…) the shrine which he dedicated to all the Apostles”. We can get an idea about the differences between the Pre-Justinianic St. John and the Holy Apostles by comparing St. John’s transept and chancel remains with the description of the Holy Apostles. Indeed, Constantine of Rhodes (cited in G. A. Sotiriou, 1924, pp. 207–208) describes the piers carrying the dome of the Holy Apostles as “quadruple in composition”. With this, the 10th century author means that, as was the practice in post 6th century domed basilicas, these piers were pierced by passages that divided them in four pars. This pier design would create a different spatial impact from the one of Pre-Justinianic St. John, which had compact piers surrounding the crossing.

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Early Byzantine Vaulted Construction in the Western Coastal Plains and River Valleys of Asia Minor of the west cross arm.279 Historical testimonies turn our attention to these possibilities, and call for a reexamination of the visible remains, in the light of comparable examples from other vaulted buildings, in search for further evidence for the nature of the original vaults of St. John.

include both hemispherical and shallow domes on pendentives in their structural fabric. The survey of the vaults of these two Justinianic churches aims to discover what distinguishes the pendentives carrying a shallow dome from the ones carrying a hemispherical dome. The identification of a possible structural difference between the lower portion of a pendentive dome and the one of a dome on pendentives would be vital in our attempt to interpret the pendentive fragments of St. John. Such a find would encourage the use of fragments from the lower portion of the vaults as evidence for reconstruction.

4. Comparable Examples Procopius expected his readers to understand something of the form of the church of St. John through its comparison with the church of the Holy Apostles. This seems to show us that the study of other monuments with a structure similar to the one of St. John can be relevant to the study of the Ephesian church. Indeed, the examination of late antique and early Byzantine monuments preserving extensive parts of their vaults can help to identify the nature of St. John’s vault fragments, which, isolated, seem to be little more than amorphous lumps of brick and mortar.

The vault structure of St. Eirene juxtaposes a hemispherical dome on pendentives and a major pendentive dome, and therefore seems to be an ideal start for our examination. W. S. George (1913, p. 44) has noted the similarity between the lower portions of these two vaults. Indeed, their brick layouts are identical, and one seems to meet the same irregularities in the spherical surface of their pendentives. Yet, there is a difference that has eluded his attention. This is found in the way in which each vault comes to contact with the arches that support it: the pendentive dome seems to spring from the sloping face of the outer ring of its supporting arches (A in fig. 100), whereas the pendentives surmounted by the hemispherical vault spring from the extrados of the arches (B in fig. 101).280 The nature of each springing seems to reflect the structural behaviour of the corresponding vault. The sloping face of an arch is better suited to counteract the lateral thrusts of a pendentive dome (fig. 102).281 On the other hand, the extrados of an arch seems to be more appropriate for the seating of pendentives that carry the considerable weight of an entire hemispherical vault, such as the dome of St. Eirene (fig. 103).

The idea for an analysis of the vault fragments of St. John within the broad context of early Byzantine vaulting sprang from the observation that their structural fabric is reminiscent of surviving vaults found in other monuments. The superimposed arched brick courses in fragments G and H evoke a rarely encountered type of vault, found in late Antique and early Byzantine Mausolea such as the ones at Spalato (Split), and Side. The pendentive remains observed in fragments A and B bring to mind the springing of the pendentive domes of Hagia Sophia and St. Eirene, at Constantinople. The existence of two superimposed vault shells in these fragments is suggestive of shallow domes with a double shell, such as the one in the crypt of the Basilica of Ilissos, in Athens. The composite brick pattern of fragment D, juxtaposing horizontal and pitched brick courses, evokes the narthex vaults of Basilica B, at Philippi and St. Eirene. The detailed study of these monuments seems to be essential to the reconstruction of the vaults of St. John on the basis of their fragments.

The same structural difference between the lower portions of pendentive domes and domes on pendentives occurs in Hagia Sophia. This can be appreciated by comparing the springing of the pendentive domes 280

This can be proved by comparing the thicknesses of the exposed faces of the broad arches that carry the two vaults. The broad arches that carry the hemispherical dome on pendentives have both their arch-rings exposed. The faces of these arches have twice the thickness of the exposed faces of the arches that carry the pendentive dome. In the latter, only the inner ring is exposed. Although the outer ring of these arches, and its sloping face are not visible, their existence can be deduced by observing the transverse broad arch that lies between the pendentive dome and the eastern hemispherical dome. The face of this arch towards the dome consists of two rings, whereas the face of the same arch towards the pendentive dome only has one ring. This seemingly minor detail has eluded the attention of U. Peschlow (1977, pl. 3), and W. S. George, (1913, fig. 22). Both authors have depicted this arch with both its faces exposed. Strangely, W. S. George (1913, p. 10, fig. 2) rectifies this mistake in his isometric drawing of the monument, where he shows clearly the pendentive dome springing from the sloping face of a concealed outer ring of the supporting arches. My remarks on the thickness of supporting arches of St. Eirene have been based on the consultation of photographs of the monument published in R. Mainstone (1988, p. 204, fig. 233), and C. Mango (1978, p. 91, fig. 126). 281 According to Rabun Taylor (1996, pp. 74–75), early Byzantine architects must have known that “domes of shallow profile tend to exert greater horizontal forces on their supports than those of semicircular profile”. R. Mainstone (1992, p. 168) notes that the horizontal thrusts exerted by the first, shallow dome of Hagia Sophia “would have been about 50 percent greater than for the second, [hemispherical] dome”.

Spherical Vaults in Hagia Sophia and St. Eirene Most of the vault fragments of St. John derive from the lower portion of the vaults, and, specifically, from the springing of the pendentives. The following paragraphs will explore the potential of such pendentive fragments to offer evidence for the reconstruction of the upper portions of the vaults. A way to explore this potential is to focus on surviving 6th century vaulted churches, and to examine the degree to which the overall form of spherical vaults is echoed by their pendentives. Hagia Sophia and St. Eirene at Constantinople would be ideal for this purpose, as they 279 The disregard for the possibility of the existence of shallow domes characterizes the reconstruction by H. Hörmann (1951, fig. 44), which suggests that St. John had six identical hemispherical domes. Both this reconstruction and the one by A. Thiel only admit a uniform vaulting pattern throughout the church’s peripheral bays.

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The Vaults of St. John the Theologian at Ephesos

100. Constantinople, St. Eirene, cross-section of the pendentive dome over the west bay of the nave, showing the interface (A) between dome and broad arches (drawing by Nikolaos Karydis, 2009).

101. Constantinople, St. Eirene, cross-section of the central dome, showing the interface (B) between pendentives and broad arches (drawing by Nikolaos Karydis, 2009).

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Early Byzantine Vaulted Construction in the Western Coastal Plains and River Valleys of Asia Minor

102. Constantinople, St. Eirene, schematic axonometric of the springing of the same pendentive dome as in figure 100. Note that the vault springs from the sloping face of the supporting arches (drawing by Nikolaos Karydis, 2009).

unlikely to be unique to the Imperial capital.284 Instead, it probably occurred in St. John at Ephesos as well, a church that included a number of spherical vaults built with circumferential brick courses.

surmounting the bays in the four gallery corners (fig. 104), with the corresponding detail in the central vault. There is no doubt that the pendentive domes of the gallery spring from the face of the supporting arches: the latter are completely covered by the vault shell.282 Also, it is very probable that the pendentives of the central dome lie on top of the extrados of the four broad arches.283 We realize that, although the lower portions of the two vaults are similar in geometrical form and brick pattern, there is an obvious difference in the way they connect with the supporting arches.

The above distinction between the springing of a pendentive dome and the one of a dome on pendentives can contribute considerably in the interpretation of vault fragments A, B, and C. As we have seen, in fragments A and B, the pendentive remains seem to spring from the sloping face of the supporting arches, rather than from their extrados. This construction detail is typical of pendentive domes similar to the one over the west bay of St. Eirene, or the ones surmounting the corner bays of the gallery of St. Sophia. Therefore, fragments A and B are probably parts of pendentive domes than parts of pendentives that originally carried hemispherical domes. On the other hand, vault fragment C includes the remains of supporting arches that probably had their faces entirely exposed; the pendentives must have rested on the extrados of the arches. This particular construction detail, so different from the corresponding one in fragments A, and B, resembles the springing of great hemispherical domes on pendentives such as the ones of Hagia Sophia and St. Eirene. Therefore, it is probable that fragment C is part of a pendentive that carried a hemispherical dome.

The examination of the spherical vaults of Hagia Sophia and St. Eirene possibly suggests a way in which we can reconstruct a 6th century spherical vault whose central portion is missing: the lower portion of a pendentive dome springs from the faces of the bounding arches, covering them either partly or entirely, whereas pendentives carrying hemispherical domes tend to be seated on top of the arches’ extrados, leaving their faces exposed. This structural difference between pendentive domes and domes on pendentives, observed in the two most important Justinianic churches of Constantinople, is

282 See R. Mainstone (1988, p. 111, fig. 136, p. 109, fig. 134, p. 55, fig. 67). 283 R. Mainstone (1988, p. 78) notes that the junction between pendentives and arches, as well as the face of the main arches are unfortunately obscured by a thick layer of 19th century plaster. Still, earlier surveys of the building, mentioned by M., have shown that the entire face of the arches, measuring 1.00m, had originally been exposed.

284

This is confirmed by A. Choisy (1883, p. 102). Having examined a wide variety of spherical vaults both in Constantinople and the provinces, the French author generally observes that “a pendentive dome never rests on the extrados of an arch: it is always fixed against the face of the supporting arch”.

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The Vaults of St. John the Theologian at Ephesos

103. Constantinople, St. Eirene, schematic axonometric of the springing of the pendentives of the central dome. Note that the pendentives spring from the extrados of the supporting arches, as opposed to their face – compare with fig. 102 (drawing by Nikolaos Karydis, 2009).

104. Constantinople, Hagia Sophia, view of the gallery. Note the pendentive dome covering one of the bays in the background.

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Early Byzantine Vaulted Construction in the Western Coastal Plains and River Valleys of Asia Minor

105. Side (South Asia Minor), East Mausoleum, reconstructed cut-away axonometric. Note the asymmetrical pendentive borders and the arched brick courses in the dome (drawing by Nikolaos Karydis, 2010).

Domes with Arched Brick Courses: from Side to Spalato

Ephesos the locus classicus of the use of this particular vaulting pattern.

The arched shape of brick courses in the fragments of the major west vaults of St. John is indicative of rare vaulting techniques, only sporadically employed in Early Byzantine architecture. Similar techniques seem to have been used in the dome of the Mausoleum in Diocletian’s Palace at Spalato, as well as in the shallow dome covering the east Mausoleum at Side. There is also a report of the use of the same technique in the shallow dome over the Crypt of St. Demetrius in Thessaloniki.285 Despite its rarity outside west Asia Minor, this vaulting technique must have occurred frequently in Ephesian monumental architecture. Indeed, the dome of the Baptistery of St. Mary in Ephesos,286 as well as the vault surmounting an octagonal reception hall, or Nymphaeum in the same city, 287 seem to make early Byzantine

The extensive, well-preserved remains of the shallow dome on pendentives of the east Mausoleum at Side seem to incorporate parts with a striking resemblance to the fragments of the west vaults of St. John.288 At this point, we should note that both the central space of the Mausoleum and the west bays of St. John are oblong in plan. The use of asymmetrical pendentive borders made of pitched bricks to mitigate the height difference between the supporting arches, and, above all, the arched courses of the pendentives, are typical of both monuments. In Side, arched courses are associated with a vault structure where the pendentives and the calotte form a continuous vertical surface (fig. 105). This form resembles a pendentive dome. The similarity between

285

6th century on the basis of its building technique. For a rough illustration of this dome structure see P. Sanpaolesi (1971, p. 43, fig. 54). 288 I have not had the chance of visiting this remarkable monument. I rely on the excellent survey published by P. Sanapaolesi (1971, pp. 21– 23, and 53–56, fig. 69–73). This includes numerous comprehensive illustrations and photographs. For a somewhat less accurate survey, which, unlike P. Sanpaolesi, includes a plan and a section of the monument, see A. M. Mansel (1978, pp. 318–323, fig. 377–381).

A. Choisy (1883, p. 102). The use of arched brick courses in the dome of the Baptistery of St. Mary was first recorded by F. Knoll (1932, p. 49). An excellent illustration and a description of the “articulazione arcuata” occur in F. Fasolo (1951, p. 6, fig. 9). This structure will be examined in detail in chapter 6. 287 The complex to which this octagonal hall belongs has been identified by C. Foss (1979, p. 51) as the palace of the governor and dated to the 286

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The Vaults of St. John the Theologian at Ephesos fragments G and H, and the vault pattern at Side seems to suggest that the fragments from the vaults of the west cross arm of St. John belonged to pendentive domes.

survived until the 20th century is only known indirectly through its reconstruction, and, therefore, any connection with St. John must remain in the hypothetical sphere.292

The Dome of the Mausoleum of Diocletian, within the famous palace the Emperor built at Spalato at the end of the 3rd century, also comes to mind when examining the vault fragments of the west vaults of St. John.289 Indeed, both the dome in Spalato and these fragments have a double shell whose intrados is made with bricks laid in arched courses. In Spalato, each of the “scales” of the bottom zone of the dome consists of 16-18 arched brick courses. The same number of courses is found in the vault unit preserved in fragment G of St. John. These similarities make the dome at Spalato a plausible model for the reconstruction of the two west domes of St. John. This reconstruction should obviously take into account the differences between the plans of the two buildings and between the frameworks of these domes.

Signs of a similar vaulting pattern, consisting of arched courses, have been discovered in a dome fragment from St. Mary’s Baptistery at Ephesos.293 Given the smallness of this fragment, it is difficult to use it as a model for the reconstruction of the domes of St. John. However, these remains, belonging to a hemispherical dome surmounting a circular hall demonstrate that the technique used in the domes at Side, Spalato, Thessaloniki, and Ephesos has known a series of variations. These variations seem to share three consistent characteristics: in most cases the vault fabric consists of arched courses; these arched courses are arranged to form segmental, rather than semicircular arches; this construction system is everywhere applied in spherical vaults with a continuous, stable curvature from springing to apex. These characteristics could serve as a guide in the following reconstruction of the western domes of St. John.

As the dome at Spalato, the west domes of St. John could have consisted of units made of arched brick courses. Whether these units formed a network suggestive of a fish’s scales in St. John as well is not certain. Nevertheless, the similarity between the structure of the dome at Spalato and fragments G and H could be regarded as an indication for the use of the same vault form in both structures. At Spalato, the dome has the same curvature as the eight pendentives. If this was the case in the vaults over the west bays of St. John, then the latter must have been pendentive domes.290

The Secondary Vaults of St. Eirene and Basilica B at Philippi The evidence offered by the solitary fragment of the aisle vaults of St. John (fragment D) is inadequate for their complete reconstruction (see figs. 78 and 92). Nevertheless, this small fragment indicates that the aisle vaults must have had a mixed structure and a composite form. Also, the existence of a groin in the fragment suggests an intersection between different vaulted surfaces. This last characteristic is found in three different Byzantine vault types: in cross vaults,294 in domical groin vaults,295 and in vaults generated from the interpenetration between barrel vaults.296 The smallness of fragment D prevents us from determining the original shape and extent of its groins, necessary for the choice between these alternatives.297 Furthermore, this same fragment does not offer enough information on the way in which this vault was inscribed into the surrounding structure, a question that does not seem to have been

On the other hand, there is an essential part of St. John’s fragments which is missing in Spalato: in fragment H, for instance, the arched courses seem to have been crowned by segmental arches built with the standard method of bricks laid radially. Is this an indication of a dome where each group of arched courses is covered by a segmental brick arch? This possibility seems to be confirmed by the examination of a shallow semidome in the substructures of St. Dimitrios in Thessaloniki.291 This structure seems to have consisted of arched brick courses arranged in a network of interlocking units. Between these units there are small segmental arches, built with radial bricks creating yet another network of superimposed arches. This structure, which this time incorporates all the elements of fragments G and H, is suggestive of how the possible pendentive domes of St. John might have looked. Yet, it remains that its only example to have

292

The description of the semidome over the crypt of St. Dimitrios can only be hypothetical as the actual structure is nothing but a post–1917 reconstruction. This is a mere echo of the original 5th century structure, known only from a schematic sketch by A. Choisy (1883, p. 102). 293 For the dome of the Baptistery of St. Mary, see F. Knoll (1932, p. 49). 294 In such a vault, elliptical groins mark the intersection between semicylindrical vaults. 295 In this case, roughly circular groins, gradually disappearing nearer to the crown, mark the intersection between vaulted surfaces with a double curvature. 296 These vaults are characterized by the intersection between barrel vaults of different size, with groins meeting before reaching the vault’s crown. 297 Several reconstructions of the aisle vaults of St. John have been proposed without adequate consideration of the above alternatives: P. Verzone (1965, pp. 605, 609) claimed that St. John’s aisles were covered by cross vaults. On the other hand, A. Thiel (2005, pp. 29–30) agrees with the reconstruction carried out on site, featuring a longitudinal barrel vault intersected by a series of transverse ones in both sides.

289 For an illustrated description of the dome of Diocletian’s Mausoleum at Spalato, see D. S. Robertson (1983, p. 257, fig. 108). For an analysis of the construction technique applied in the building, analyzed within the broad context of late Antique dome construction, see P. Sanpaolesi (1971, p. 10). For two very good photographs of the dome’s structure see R. Mainstone (1988, fig. 199). The similarity between the structure of St. John’s vault fragments and the one of the dome in Spalato has been noted by A. Thiel (2005, p. 43). 290 Indeed, the system of the arched brick courses, as used in Spalato, seems appropriate for vaulted surfaces with a single curvature, where there is no interruption caused by the transition from the pendentive to the dome. 291 For St. Dimitrios, see G. and M. Sotiriou (1952), and R. Krautheimer (1986, pp. 125–128).

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Early Byzantine Vaulted Construction in the Western Coastal Plains and River Valleys of Asia Minor thoroughly examined until now.298 Given the limits of fragment D as source of information, the examination of aisle vaults of churches comparable to St. John assumes a considerable importance in the reconstruction of the aisle vaults of the church. Two such cases are found in Basilica B, at Philippi, and St. Eirene, at Constantinople. Indeed, both structures are almost contemporary to St. John, and seem to illustrate the use of fairly similar vaulting forms, techniques, and materials.299 The domical groin vaults of the narthex of St. Eirene have been chosen because their composite structure, including both horizontal and pitched brick courses, is reminiscent of fragment D. The aisle vaults of Basilica B, at Philippi, like the ones of St. John, seem to have been divided in oblong cells, which, in this case, were marked off by transverse arches. The examination of these vaults may give us an important insight into the nature of the Ephesian basilica’s original aisle vaults. Even failing to betray the exact form of the vaults above the aisles of St. John, these comparisons can at least reveal the issues and challenges with which early Byzantine church builders were faced when called to design such secondary vault structures.

106. Constantinople, St. Eirene, aisle vaults, cut-away axonometric (drawing by Nikolaos Karydis, 2008).

St. John’s fragment D seems to be in many points similar with parts of the domical groin vault covering the northeast bay of St. Eirene’s narthex.300 The foot of this vault consists of horizontal courses similar to the ones of fragment D – this time with their surroundings intact (fig. 92). These courses, although shaped to the curve of the vault, are really oversailing horizontal courses,301 a prolongation of the pilasters that carry the vault. Thanks to this prolongation, the proper vault structure, which consists of pitched bricks, is raised considerably above the springing line of the vault. Thus, the span to be covered by the “real” vault structure is reduced, facilitating construction without centering. This construction process consists in laying pitched brick courses parallel to the sides, and interlocking along the diagonals, where groins are formed. This study of the narthex vault of St. Eirene seems to explain the role of some of the details observed in fragment D, such as the existence of a groin, and the alternation between horizontal and pitched courses.

Fragment D, however, could not have been part of a domical groin vault such as the one over the north bay of the narthex of St. Eirene. The systematic use of this vault type in an aisle requires the articulation of the space into more or less centralized rectangular bays. In the aisles of St. John, such an articulation seems to be undermined by the misalignment between columns and their corresponding internal pilasters. If there were any bays, then these would have not only been irregularly shaped, but also considerably oblong. Their covering by centralized vaults, such as groin vaults, would have therefore been problematic, but not impossible.302 The incompatibility between such a groin vault and the shape of the aisle bays of St. John is confirmed by the fact that, in St. Eirene, the use of domical groin vaults has been limited to the square bays of the narthex. The oblong bays of the aisles in the same church have been covered by different vaults, without groins, and therefore different from the vaults of St. John (fig. 106). Looking for another case of aisle vault surmounting oblong bays, we turn to the aisles of Basilica B, at Philippi, and to their vault fragments, whose shape and structure seem to have had many points in common with the ones fragment D in St. John (fig. 107). Indeed, the aisle vault fragments of both churches consist largely of pitched brick courses, laid parallel to the supporting arches, so as to interlock along diagonal ridges, or groins.

298 A. Thiel (2005, pp. 30–31) and H. Hörmann (1951 p. 98) have not given any evidence for the way the vault connects with the arches that carry it, and for the nature of its backing. 299 The Justinianic phase of St. John is dated between 527 and 548. St. Eirene started being built in 532, but parts of it were remodeled in the th 6 and the 8th century. The date of the aisle vaults is unclear, but it is likely that they belong to the first phase (see W. S. George, 1913, p. 39). The date suggested by P. Lemerle (1945, pp. 415–518) for the building of Basilica B at Philippi, is shortly before 540. The similarities between St. John, St. Eirene and Basilica B are found in the basilican form, the existence of pendentive domes over oblong bays in the naves, the ample use of vaults with bricks set on edge, the size of bricks and thickness of the mortar beds. 300 For a survey of this vault see W. S. George (1912, p. 37, fig.17) and, secondarily, C. Mango, (1978, p. 12, fig. 7). 301 Oversailing Horizontal Courses: courses that corbel out to form a vaulted surface.

302

Indeed, in the south aisle of Hekatontapyliani, on Paros, the misalignment between columns and piers, and the irregularly shaped bays did not preclude the construction of cross vaults. Yet, unlike St. John at Ephesos, Hekatontapyliani has bays that are almost square, a shape that facilitates the construction of cross vaults and, probably makes it possible even over a slightly irregular shape. For these vaults, see H.H. Jewell, and F.W. Hasluck (1920, pp. 33–34).

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The Vaults of St. John the Theologian at Ephesos

107. Philippi, Basilica B, view of north aisle looking west. Note the aisle vault remains at the junction between pier and colonnade.

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Early Byzantine Vaulted Construction in the Western Coastal Plains and River Valleys of Asia Minor

108. Philippi, Basilica B, aisle vaults, reconstructed cut-away axonometric based on the extant remains shown with a grey outline (drawing by Nikolaos Karydis, 2008).

The fragments of Basilica B, however, clarify an aspect of the vault structure, which could not be properly understood in St. John: in the aisle vaults of Basilica B, the groins did not reach the crown of the vault surmounting each bay. Instead, the pair of groins in each of the narrow sides met before reaching the apex of the vault (fig. 108). These groins marked the line of intersection between a wide, longitudinal barrel vault, and a series of narrower, transverse barrel vaults, which corresponded to the arches of the side colonnades.

the transverse ones that penetrate it. It is very probable, therefore, that, as in the aisles of Basilica B, in the ones of St. John, the vaults were the result of an interpenetration between pitched barrel vaults of unequal size.303 Although fragment D offers some information about the nature of the aisle vaults and their connection to the external walls, it does not offer any evidence about the backing of vaults, their connection to the arches of the first floor colonnade, and the nature of the gallery floor above them. Basilica B at Philippi, on the other hand, preserves extensive structural fragments of these areas, fragments of a structure quite comparable to the one of St. John.

It is very likely that fragment D formed part of a similar vault pattern, which allows the small, transverse barrel vaults of each side to be completely independent. Thanks to this independence, the impact of the misalignment between the opposite points of support on the vault itself would have been mitigated. The existence of a composite vault like the one at Philippi over the aisles of St. John seems to be confirmed by fragment D, in which, the longitudinal vault seems to be both higher and wider than

303

The main difference between the two cases seems to lie in the nature of the barrel vaults: in St. John, they seem to have been perfectly semicylindrical, whereas in Basilica B, they seem to have been shallower and to have had a double curvature. Furthermore, the aisle vaults of Basilica B seem to have consisted entirely of bricks set pitched on the edge, and do not include any horizontal courses.

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The Vaults of St. John the Theologian at Ephesos One of the most interesting finds in Philippi is the surviving solid fill laid on top of the shell of the aisle vaults, and forming the floor of the gallery (fig. 109). This mass seems to be made of marble blocks in second use, (mainly parts of ancient architraves, capitals, cornices etc.) laid in a way that allows them to interlock, and which establishes a bond with the pier structure. Traces of such a floor, made of marble spolia, were discovered in 1962, in St. John.304 It is therefore probable that the surviving gallery floor at Philippi was built along the same lines as the one of St. John. At Philippi, the thinness of the solid infill between the apex of the vault shell and the gallery floor, probably less than 10cm, is remarkable (see fig. 108).305 There is a contrast between the slenderness of this component, and the excessive thickness (around 1m) given without corroborative evidence to its equivalent in St. John’s reconstructions proposed so far.306 Our examination of the thin gallery floor structure of Basilica B, echoing similar structures in other Justinianic churches, seems to indicate that, in St. John, the inert fill between aisle vaults and gallery floor was probably far thinner than the one appearing in most graphic reconstructions of the monument. Another aspect of the reconstruction of St. John that the aisle vaults of Basilica B could clarify regards the degree of structural continuity and bond between vaults and supporting arches. At Philippi, the structure of the barrel vaults covering the aisles is independent from the fabric of the arches.307 The team that restored a portion of the aisle vaults of St. John on site has overlooked the possibility for such an interruption between vault and arch structure (fig. 110). Yet, this interruption is by no means a particularity of Basilica B, at Philippi; it is also typical of a broader Byzantine building practice, according to which unequally loaded parts of the structure are separated by vertical joints.308 There is no reason to believe that St. John deviated from this general practice. It is therefore likely that the aisle vaults of St. John and the arches that carried them did not merge, but were separated by a joint.

109. Philippi Basilica B, detail of aisle vault fragments showing remains of gallery floor consisting of reused stone members.

304

See A. Thiel (2005, pp. 26–27). In order for this thinness to be achieved, the builders seem to have used stone pieces whose lower sides are shaped to form the negative of the vaults below them. The pieces chosen often derive from components that lend themselves to such a use, often including an inherent “feather edge”. This attempt to limit the thickness of the inert fill between vault and gallery floor, obviously related to the will to minimize the dead loads of the structure, must have resulted from aesthetic considerations as well. Such thinness serves to make the horizontal wall mass between aisle and gallery as less obtrusive in elevation as possible. 306 For instance, A. Thiel (2005, p. 25) estimates the floor of the gallery to be 80–100 cm thick. 307 At Philippi there is a joint between the aisle vaults and the supporting arches. The two elements are also made of different materials: dressed stone for the arch voussoirs and brick for the vaults. 308 Auguste Choisy (1883, pp. 110–115) was one of the first researchers to spot this general tendency in Byzantine building. 305

110. Ephesos, St. John the Theologian, west cross arm, north aisle, mid-20th century partial restoration.

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Early Byzantine Vaulted Construction in the Western Coastal Plains and River Valleys of Asia Minor The examination of the surviving vaults of Basilica B at Philippi has offered an insight into the nature and articulation of the aisle vaults of St. John. It can also help to explain the requirements that seem to have necessitated the use of such a complicated vault pattern. The design of the church at Philippi, emulating in many respects the appearance of a timber-roof basilica (with its dense colonnades, and its thin piers),309 possibly aimed at reducing the aesthetic impact of secondary vaults on the internal screen elevations.310 The stylistic imitation of a basilican, timber-roof structure must have required that these vaults are as compact as possible. This must have led the architect of Basilica B to lower the springing level of the aisle vaults in order for it to coincide with the springing of the supporting arches. The result was the creation of a vault form that allowed the ingenious integration of the two components, arches and vault, within a single, compact structure.311

Hagia Sophia and Sts. Sergios and Bakchos, at Constantinople, as well as Hekatontapyliani, on the island of Paros, constitute rare cases of Early Byzantine churches, where the original gallery vaults have survived. Of the plans of these three churches, only the one of Hekatontapyliani seems to be typologically comparable to St. John at Ephesos.312 The plans of Hagia Sophia and Sts. Sergios and Bakchos are, of course, typologically different from the one of the Ephesian cruciform church. Yet, the building materials (bricks and mortar) and construction techniques (pitched-brick vaulting) used in their secondary vaults are reminiscent of the ones found in the aisle vault fragments of St. John. The aisles of the transept of Hekatontapyliani are covered by a barrel vault springing from the same level as the arches of the colonnade. This vault is intersected by a series of transverse barrel vaults, in a way similar to the one observed in Basilica B at Philippi. On Paros, this compact vaulting pattern is not repeated in the galleries. The latter are “roofed with barrel vaults which have their springing line above the crown of the (…) arches of the upper arcade”.313 In this church, the vaults of the gallery seem to be a steeper version of the aisle vaults below them.

The same influence of design issues on the form of the aisle vaults must have occurred in St. John, a church which also combines the vocabulary of standard basilican construction, with the requirements and possibilities of vaulting. But whereas at Philippi nothing in the aisle plan reflects this vaulting solution, at Ayasoluk, the rhythmic sequence of spur walls compartmentalizing each aisle into rectangular bays seems to show that there is also an inverse influence: the one of a vaulting pattern, which tends to resemble a series of groin vaults, to the design of the church’s plan. We realize that the comparison with churches such as St. Eirene and Basilica B does not only assist the interpretation of vault fragments; it also reveals several aspects of the design procedure, and some of the stylistic concepts that influenced it.

This last characteristic echoes, to a certain extent, the secondary vaulting pattern in Hagia Sophia. In the Great Church, the north and south gallery vaults, although different from the ones in Hekatontapyliani’s transept, also seem to constitute a steeper version of the aisle vaults. As Choisy (1883, p. 108) has noted, the aisles are covered with domical groin vaults, while the galleries above them are roofed with pendentive domes. According to the French author, “this distinction between aisle and gallery vaults is not limited to Hagia Sophia”, but is also typical of many other Byzantine monuments.

Gallery Vaults in the Justinianic Churches of the Aegean Coastlands and Constantinople

The church of Sts. Sergios and Bakchos seems to confirm the tendency to give the gallery vaults a steeper profile than the one of the vaults over the aisles (fig. 111).314 Indeed, the south ambulatory of the church juxtaposes a barrel vault on the ground floor, and a series of domical groin vaults on the floor above. In the north ambulatory, the elevated barrel vault of the gallery, with its springing raised considerably higher than the apices of the supporting arches, contrasts with the barrel vault covering the floor below, which rests directly on a horizontal entablature.

Fragments J and K constitute our solitary source of information about the original form of the gallery vaults of St. John. As these fragments do not include parts of the vaults themselves, the evidence they can offer is limited. A simple overview of the ways in which galleries were covered in other Justinianic churches could not fill this lacuna. Such an overview could, however, bring to consideration the range of early Byzantine forms and building techniques employed in gallery vaults. The knowledge of these forms and techniques could prove to be crucial to the interpretation of the few fragments from the galleries of St. John.

312

The similarities between Hekatontapyliani and St. John are found in the cruciform plan, the alternation of piers and columnar screens, the use of vaulted forms such as the barrel vaults over the aisles, and the central dome on pendentives. These similarities seem to attest that, in Hekatontapyliani, we are dealing with an interpretation of a typical Early Byzantine architectural program with local, Parian techniques, based on the dexterous use of dressed stone, typical of the island. The two monuments have been compared by G. A. Sotiriou (1924, p. 223), A. Orlandos, (1952, p. 48), and P. Lemerle (1953, pp. 536–541). A. Orlandos regarded both monuments as “cruciform basilicas with unequal cross arms”. P. Lemerle stresses that St. John has been a “Martyrium”, whereas Hekatontapyliani was a “Basilica”. C. Mango (1978, p. 86), sees Hekatontapyliani as a “transept basilica”, and St. John as a “cruciform church”. 313 See H. H. Jewell and F. W. Hasluck (1920, pp. 34–35). 314 See T. Mathews (1971, pp. 47–50).

309 Indeed, according to R. Krautheimer (1986, p. 253), “the architect who (…) built Church B at Philippi (…) based himself on the plan typical of local timber roof basilicas”. 310 The tendency to avoid the appearance of the faces of the secondary vaults in the elevations is observed in Hagia Sophia. In this church, Anthemios and Isidoros tried to hide the structure of the aisle vaults by making the screens independent from them. The vaults rest on a distinct group of columns, set back from the screen itself. See R. Mainstone (1988, p. 277, pl. A8). 311 This tendency of the Byzantine builders to “diminish the open spaces over which their vaulting had to fly” has been noted by W. S. George (1912, p. 35).

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The Vaults of St. John the Theologian at Ephesos

111. Constantinople, Sts. Sergios and Bakchos, cut-away axonometric. Compare the steep profile of the gallery vaults with the profile of the aisle vaults on the left (drawing by Nikolaos Karydis, 2006). instead, a tendency to produce varied vault forms by modifying slightly the profile of a single vault type. This modification often consisted in giving the gallery vaults a steeper profile than the aisle vaults. This conclusion calls for a return to St. John’s vault fabric to investigate whether the vaults of the gallery were not a mechanical reproduction of the compact barrel vaults of the aisles, like the one championed by earlier reconstructions, but followed a different layout. This could have been a variation on the theme of the aisle vaults created by elevating the springing of the barrel vault and, thus, stressing the vertical axis, as in Hekatontapyliani, Hagia Sophia, and Sts. Sergios and Bakchos.

In this church, the view from the ground floor towards the gallery vaults is obstructed by the tympanum walls. Looking at the galleries through the columnar screens, it is difficult to distinguish the shape of the vaults. What we rather see is a dark zone above the arches. We realize that, even though galleries and aisles of the above churches had similar plans, the vaults of their gallery did not necessarily reproduce the pattern of the aisle vaults below them. Still, the vault forms in the two floor levels were seldom entirely different.315 There was, 315 Two rare examples are the south ambulatory of Sts. Sergios and Bakchos as well as the inner narthex of Hagia Sophia. Both cases combine a barrel vault with a domical groin vault.

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5. Previous Reconstructions

The Focus on Uniformity H. Hörmann has been criticized, perhaps unjustly, for understating the design and construction differences between the nave and the eastern part of St. John, which includes the transept and the chancel. Yet, H. Hörmann has acknowledged the existence of two building phases (with a small time period between them).322 Still, he does not seem to have examined the possibility of the impact of this phase difference on the structural form of the vaults of St. John. Indeed, in his graphic reconstruction, the 6th century monument is represented with a homogeneous design, while the structural and formal discrepancies of the church are relegated to the sphere of construction particularities of secondary importance. One of the key characteristics of this design is its uniform vaulting pattern: according to the Austrian archaeologist all the bays of the 6th century church were covered by domes on pendentives. The same design uniformity is found in the reconstruction of A. Thiel, representing a repetitive sequence of pendentive domes.323

There have been many attempts to reconstruct the original form of the Justinianic phase of St. John at Ephesos. Two of these reconstructions, namely the ones by H. Hörmann (1951), and A. Thiel (2005), have been tremendously influential in the way we perceive St. John today. The earliest reconstruction was carried out under the supervision of the Austrian excavators who took over form G. A. Sotiriou, H. Hörmann and J. Keil. Their drawings show the bays of St. John covered by a series of identical hemispherical domes on pendentives.316 One of the most characteristic, but unfounded aspects of this reconstruction is a series of flying buttresses, projecting above the roofs of the galleries.317 F. Hueber and M. BüyükkolancÕ, in their reconstructions, maintained the hemispherical form of all the domes, but were the first to reconstruct the central dome over the crossing with its base pierced by windows.318 A. Thiel thoroughly revised these reconstructions. His reconstruction, following a suggestion that had originally been made by P. Verzone but had not been accompanied by drawings,319 shows a solitary fenestrated hemispherical dome on pendentives over the crossing, and five pendentive domes over the cross-arms.320 These reconstructions were largely hypothetical. Before we advance with yet another reconstruction of the monument, it would be useful to establish the extent to which these previous reconstructions are confirmed by the new evidence for the original form of the vaults of St. John.

The tendency to impose a homogeneous character on a structure whose surviving parts are quite varied, echoes 20th century architectural aesthetics, and is not based on evidence from the archaeological remains. Indeed, by failing to examine pendentive fragments from the transept of the church, the two authors overlook their important structural difference with the pendentive fragments of the west cross arm. This should be regarded as another serious indication for the existence of two distinct and distant phases in the building of St. John. The impact of these phases on the vault structure of the church seems to have been underestimated by the two Austrian authors.

Emphasis on Geometry and Form The focus on geometry and form as opposed to construction characterizes the graphic reconstruction proposed by H. Hörmann and the one by A. Thiel. In both cases, St. John’s original vaults are represented in plan, section, and axonometric drawings, which do not offer any information about the brick pattern of vaults.321 This approach tends to underestimate evidence from construction details. This tendency probably had a major influence on both proposals. Indeed, for both graphic reconstructions the shape of the vaults is shown to derive from the geometrical shape of the bays below them: as the latter are rectangular, the vaults above them are depicted by both A. Thiel and H. Hörmann as elliptical in plan. This choice seems to demonstrate that both A. Thiel and H. Hörmann have given more importance to the geometry of bays than on surviving fragments from the structure of the vaults as, for instance, vault fragments G and H. These fragments have in, fact, a dramatic significance for the graphic reconstruction of the vaults of the nave.

Consistency with Early Byzantine Vaulting Practice A. Thiel and H. Hörmann have not given construction fragments the weight they deserve as evidence. This has led them to graphic reconstructions that seem to deviate in their details from Early Byzantine practice, as it is observed in most monuments contemporary to St. John. This deviation can be mainly seen in the reconstruction of the secondary vaults. Thus, it is doubtful whether the gallery and aisle vaults were identical, as both authors suggest.324 In most early Byzantine churches, the gallery vaults have a different and usually steeper profile from the vaults below them. That the secondary vault pattern of St. John followed this trend is confirmed by a closer observation of vault fragments J, and D. Also, the 322 H. Hörmann (1951, p. 100) has identified “a phase difference (…) between the nave and the transept.” According to P. Verzone (1965, pp. 609–610), “the monument presents a particularity that has been noted but not explained. The walls of the transept and of the presbytery have a structure which is different from the one of the walls of the nave”. Verzone also refers to the design difference between nave and transept, and to the vertical joint between the two parts of the church. All these characteristics have been interpreted as indications of different phases in H. Plommer (1962, p. 124). 323 A. Thiel (2005, p. 47) states: “there was very little or no intermediate time between the building of the transept and the building of the nave.” 324 See A. Thiel (2005, pp. 109–110), and H. Hörmann (1951, table LXIX, pp. 165–169).

316 See H. Hörmann (1951, pp. 165–169, fig. 42, 44, and tables LXIX, and LXX). 317 H. Plommer (1962, p. 126) “[questions] both the aesthetics and the firmness of H. Hörmann’s buttresses.” 318 See M. Büyükkolanci (2000, p. 51). 319 See P. Verzone (1965, p. 609). 320 See A. Thiel (2005, p. 110). 321 See H. Hörmann (1951, pp. 92–103, tables XX – XXVII) and A. Thiel (2005, pp. 42–44)

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The Vaults of St. John the Theologian at Ephesos combined thickness of the aisle vaults and the gallery floor is shown by both authors to exceed 1 m. This thickness is more than 2.5 times bigger than the equivalent one in Basilica B at Philippi, and at least 2 times bigger than the one in St. Eirene.325

associated with the initiative of Justinian and Theodora, were roofed with spherical vaults. According to the remains examined, these vaults must have sprung from two pairs of semi-circular arches of unequal height. Indeed, given the dimensions of the bays, the transverse arches spanning the nave must have been higher than the arches covering the lateral screens. This difference in height, probably reaching 60cm, would have probably created a serious impediment in the erection of a hemispherical vault on pendentives. Such a vault normally requires the arches below it to be of equal height in order to support the circular base of the dome.

Conclusion Although earlier reconstruction proposals formed part of crucial publications that constitute significant steps in the study of the monument, they do not give enough attention to construction detail, and the choice of vault forms they represent is not entirely corroborated by the evidence available. For these reasons, they cannot be considered ideal sources for our survey of Early Byzantine vaulting practices in west Asia Minor. For the needs of our survey, a new graphic reconstruction of the vault fabric is required, one that will take into account all available evidence presented in the previous paragraphs: evidence from vault fragments, literary sources, and contemporary church structures.

Early Byzantine builders have responded to this difficulty in two different ways. The first consists in giving the narrow arches an elliptical shape in order to raise their crown to the same level as the crown of the wide arches. This solution was applied in St. Eirene, without, however, diminishing the height difference between the arches to zero. A second resolution would be to abandon the form of the hemispherical dome altogether, in favour of a pendentive dome. In such a vault, the pendentives join each other in pairs on top of the apexes of the narrow arches. These pendentives and the saucer dome they carry form a continuous spherical surface. This solution is observed in the west bay of St. Eirene,326 in the corner bays of the gallery of Hagia Sophia,327 and, quite probably, in the great central bay of Basilica B, at Philippi.328

6. Graphic Reconstruction The purpose of the present graphic reconstruction proposal is primarily to identify the original structure of the church’s vaulting components on the basis of the vault fragments analysed in the first part of this chapter. Here, quite unlike previous graphic reconstructions, the emphasis is given on the correct, accurate depiction of vault fragments, rather than on the conjectural representation of the complete monument in its entirety. The interpretation of these fragments in the light of evidence from various sources forms the basis for a new tentative reconstruction of the vaults of St. John.

There are two indications for the visualisation of the nave of St. John with pendentive domes. The first indication is the rectangular shape of the bays itself. According to the previous paragraph, this bay shape does not easily adapt to the hemispherical vault on pendentives. The second and most important indication comes from the photographed fragments of the pendentives of the vaults: their structure, consisting of arched courses of brick, cannot easily be interrupted by a horizontal ring, which would serve as the base of a hemispherical vault. Instead, this structure is more likely to have continued, above the pendentives, forming a pendentive dome (fig. 112).

Primary Vault System The primary vaults cover the central, six major bays of St. John. Both the vault fragments and the documentary evidence examined indicate that these bays were covered by at least two different types of primary vaults: pendentive domes and domes on pendentives. Examining the fragments of the major vaults, we realized that these reflect the use of two different vaulting patterns, possibly indicating the existence of a phase difference between the vaults over the west cross arm (i.e. the nave) and the vaults of the east part of the church, (transept and chancel). For this reason, we have chosen to reconstruct the two groups of major vaults separately.

In the nave, the builders maintained that the main, central portion of the pendentive domes would be square, rather than oblong in plan. This was achieved by giving the pendentive border on top of the narrow arches more than twice the thickness of the pendentive border on top of the wide arches. Thus, four arched surfaces of equal height were created, ready to support a pendentive dome with a square plan (figs 94 and 95). Our understanding of this vault structure leads us to exclude the possibility for the existence of domes built on oval plans, championed by H. Hörmann, and A. Thiel, despite the fact that such vaults have often been considered the only possible domical solutions over rectangular bays.329

The nave of St. John seems to have been covered by quite a sophisticated structure. The particular vaulting pattern observed during the examination of vault fragments G and H, as well as the 12th century report by G. Tornikes, seem to indicate that the two rectangular central bays of the nave of the church, belonging to the building phase

326

See W. S. George (1913, p. 42, fig. 22). See R. Mainstone (1988, p. 81, fig. 67). 328 See P. Lemerle (1945). 329 See H. Buchwald (1984, p. 211). 327

325 For Basilica B, see P. Lemerle (1945, plates LXXXI–LXXXII). For St. Eirene, see U. Peschlow (1977, plate 3).

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112. Ephesos, St. John the Theologian, west cross arm (nave), pendentive domes, reconstructed axonometric. This hypothetical reconstruction is based on fragments recorded by H. Hörmann in 1951 (drawing by Nikolaos Karydis, 2008). a “dome base” similar to the one of H. Sophia.330 A. Thiel (2005, p. 48), on the other hand, based on comparisons with the vaults of the gallery of H. Sophia, and the ones of St. Eirene, claims that the backing of the arches must have reached the 2/3 of their total height. In the absence of fragments allowing us to examine this question, we must accept that both solutions are possible.

The main fabric of the pendentive domes themselves can be graphically reconstructed in two alternative ways. Like the dome of the mausoleum at Side, the pendentive domes of St. John could have consisted of arched courses of brick laid both diagonally across the corners of the vault, and parallel to the arches, forming interlocking and superimposed wedge-shaped components (fig. 112). Still, in St. John, each of these components seems to have been crowned, and separated from the higher ones, by a brick arch made of half-size bricks laid in a radial way. Alternatively, the arch in the pendentive fragment G, photographed by H. Hörmann’s team, could have formed part of a whole, dense network of superimposed segmental arches, suggestive of the layout of a fish’s scales (fig. 113). The voids between these superimposed arches would then have been filled with arched courses of brick.

With the vaults surmounting the eastern bays of the church (i.e. the bays of the transept and the chancel) we are on firmer ground, as we rely mainly on evidence from pendentive fragments that still survive and can be examined in detail. None of these fragments preserves parts of the central portion of the vaults. Due to this lack of evidence, earlier reconstruction proposals have been faced with the usual dilemma between pendentive domes and full domes on pendentives. 331 The following

Both the thickness and the exterior treatment of this structure are unknown. The latter would depend on the extent to which the piers continued above the springing of the two arches. Hörmann, has suggested that the pier structure continued up until the crown of the arches, constituting a massive backing for each arch and forming

330

See H. Hörmann (1951, p. 167, fig. 44, table LXIX). In earlier reconstructions, the choice between the two forms was based on arbitrary assumptions and stylistic criteria. Indeed, A. Thiel (2005, pp. 47–48), claims that “if shallow domes occurred in the nave, then the vaults in the rest of the church must have had similar vaults”. In addition to this, he suggests that if the major bays of the east parts of the church had been covered by full domes on pendentives, then “this part would have been given a gravity that does not fit to the general aspect of the church”.

331

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The Vaults of St. John the Theologian at Ephesos

113. Nave, pendentive dome, alternative reconstruction - compare with figure 112 (drawing by Nikolaos Karydis, 2008).

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114. Ephesos, St. John the Theologian, reconstructed axonometric of overall structure (drawing by Carolina Vasilikou and Nikolaos Karydis).

paragraphs will attempt to resolve this dilemma through a new interpretation of vault fragments A, B, and C. Indeed, as we have seen, these pendentive fragments, and in particular the connection between pendentives and arches can be used as proof for the overall form of the vaults.

demonstrate that the pendentives must have consisted of a double shell. This could either have been limited to the area of the pendentives, or extended to the dome as well. H. Hörmann (1951, p. 167) explored this second possibility, by suggesting that this double shell continued above the pendentives, forming a reinforcement zone which acted as a tension ring in the base of the dome.333

Each of the three spherical vaults of the transept rested on four semi-cylindrical broad arches of equal height. As in the nave, each of these arches consisted of two concentric rings of radial bricks.332 A border of bricks was laid against the sloping face of the outer rings of the arches. This intermediate zone between arches and pendentives consisted of three courses of bricks laid on edge. The pendentives themselves were constructed in the conventional manner, with standard size bricks forming circumferential courses, laid at a gradually increasing inclination from the horizontal. The vault fragments

As we have seen,334 the connection between arches and pendentives in vault fragments A and B, is similar to the one observed in a series of pendentive domes preserved in St. Eirene and Hagia Sophia (see figs. 100, 102). Indeed, in both the fragments of St. John, and the Constantinopolitan pendentive domes, the vault proper lies against the sloping face of the arches. On the other hand, the nature of the connection between pendentive and supporting arch observed in fragment C, which derives from the central vault, is typical of the lower

332 The inner ring of these arches, built with exceptionally large bricks (type C: 50x35cm), was thicker than the outer ring, which was made of standard bricks.

333

A. Thiel (2005, p. 47), contests the existence of such an enlargement in the base of the dome of St. John. 334 See Chapter 3, Section 4.

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The Vaults of St. John the Theologian at Ephesos portion of a dome on pendentives. We have shown that, in most similar 6th century domes, the pendentives rest on top of the extrados of the supporting arches (see figs 101, 103). Such a connection between arch and pendentive is observed in fragment C. These observations lead us to visualize the major north and south vaults of the transept as pendentive domes, built with bricks set in circumferential courses, and the central vault as a hemispherical dome on pendentives (fig. 114). This vaulting pattern is characterised by the prominence of the central dome. The role of this element as the culminating point of the design not only echoes the emphasis given to the crossing by the cruciform plan of this particular monument, but is also regularly encountered in early Byzantine religious architecture. At this point, we should note that in many churches of this period, the central dome is raised on a drum pierced by windows. This detail is similar to the one found in 6th century churches such as Hagia Sophia, St. Eirene and Sts. Sergios and Bakchos. In these churches, the structure of the central dome broadens in its base, often to form a fenestrated cylindrical drum. Waiting for the discovery of further evidence for the external appearance of the central dome of St. John, we would be tempted to reconstruct it with a low fenestrated drum, following the example of the few surviving Early Byzantine domed churches.

115. Transept, typical aisle vault, reconstructed axonometric (drawing by Nikolaos Karydis, 2009).

Secondary Vault System It has been difficult to establish the form of the aisle vaults. The misalignment between the columns and the pilasters of the aisles of St. John limits the possibility for the existence of centralized vault forms, such as groin vaults, or pendentive domes over the aisle bays.335 The only surviving fragment (D) from the aisle vaults could therefore be considered as part of a barrel vault. The existence of groins in the fragment could betray the interpenetration between this vault and smaller, transverse barrel vaults, starting from the arches on top of the screen colonnades on one hand, and on top of the wall’s buttresses (or columns) on the other (fig. 115). This seems to be one of the few vaulting solutions to be compatible with the oblong shape of the bays, resembling to a certain extent the aisle vaults of Basilica B, at Philippi.336 The structure of the aisle vaults has a composite character. Their supports were connected with arches built with bricks laid radially, and often consisting of multiple rings of bricks. The face of each of these arches marked the beginning of a barrel vault built with bricks laid on edge. These vertical brick courses interlocked along the diagonals of each bay, creating groins. As our reconstruction shows, the aisle vaults proper did not form part of the same surface as the arches between columns

116. Ephesos, St. John the Theologian, transept, reconstructed axonometric of aisle vaults (drawing by Nikolaos Karydis, 2009). and pilasters. The reconstruction carried out on site is wrong in this respect (see fig. 110). Indeed, as fragment D clearly shows, not only had the vaults a different structure from the arches next to them (pitched brick courses, as opposed to radial ones) but they were also separated from these arches by vertical joints.

335 Indeed, a close inspection of the plan reveals that there are at least four bays in which the screen columns are not in the same axis as the pilasters of the external wall. Similar irregularities occur in the aisles of St. Mary, at Ephesos. 336 Cf. G. A. Sotiriou (1924, p. 143).

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Early Byzantine Vaulted Construction in the Western Coastal Plains and River Valleys of Asia Minor The secondary bays of the east part of the church had the same shape and proportions with the ones of the west cross arm (with the exception of the external walls, where independent columns take the place of pilasters). This seems to indicate that the two parts had similar aisle vaults. Even that way, however, a variation would have been required in the irregularly shaped bays next to the four piers of the crossing. The protrusion of the piers within the bay, giving the latter an “L-shape”, suggests that the vault over the bay was formed by two barrel vaults, probably built with pitched bricks, and interlocking along a diagonal line of intersection (fig. 116).337 We now turn our attention to the vaults over the gallery and the narthex. Masonry fragment J, described above, seems to indicate that the vaults of the galleries differed in their steepness from the aisle vaults. They probably consisted of a barrel vault springing from a higher level that the crowns of the arches supporting it. The comparisons drawn with churches such as Hekatontapyliani, and Sts. Sergios and Bakchos, seem to confirm this hypothesis. Yet, the absence of surviving fragments from the gallery vaults limits our knowledge about their structure. There is no direct evidence for reconstructing the vaults that surmounted the bays of the narthex and the west gallery above it.338 However, the examination of the plan of these spaces may give us some clues about the form of their vaults. In these spaces, the inward stance of the spur walls or, in the case of the galleries, the engaged columns, must have transformed what could have been an axial corridor into a rhythmically articulated design.339 A vault pattern consisting of individual cells would have echoed such an articulation. These cells can be visualised as pendentive domes, or as groin vaults. Still, this reconstruction is completely hypothetical. Until further proof for the form of the gallery vaults is forthcoming, it might be best to withhold judgement on this matter.

337

Cf. A. Thiel (2005, p. 30). H. Hörmann (1951, pp. 160, 166), based on the 14th century account of Ibn Battuta, reconstructs the west gallery with five hemispherical domes on pendentives. Chr. Strube, (1973, p. 122, cited in A. Thiel, 2005), has questioned the validity of this reconstruction. 339 For the engaged columns in the west gallery, see H. Hörmann (1951, p. 131), as well as A. Thiel (2005, p. 25). 338

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Chapter 4 The Vaults of Building D at Sardis

The vestiges of Building D offer very limited evidence for accurately representing the original vaults of the monument. However, they give us the exceptional opportunity to observe internal parts of the structure, such as the core of the piers and the backing of the vaults, which, elsewhere, are found concealed within an external shell. Furthermore, the few remains of the shell of the vaults, despite their small size, have the potential to reveal a lot about the structural fabric of which they formed part. Therefore, although Building D does not offer extensive information about the external appearance of its vaults, it contributes remarkably to our research by exposing structural parts and construction details that reveal aspects of Early Byzantine vaulted construction that have been rarely studied so far.

117. Sardis, Building D, view of southeast pier from the north. Note the vault fragment (A) on the top.

Auguste Choisy was the first to notice the importance of the remains of Building D.340 Although the plan of the building published by the French author is not as accurate as one might expect, his axonometric drawing gives crucial information about a part of the vaults of the building that no longer survives.341 Even though this important piece of evidence only concerns a limited part of the vaults of Building D, it helps to understand the nature and initial role of surviving vault remains. As it will be shown, such an understanding is essential for the graphic reconstruction of the original vaults of the monument.

the church. The location of one of these fragments (Fragment A) on the northwest corner of the southeast pier betrays its former role as part of the springing of a pendentive, or rather as the intermediate zone between the springing of a pendentive and its supporting arches (fig. 117). Traces of a similar pendentive-related component are found on top of the southwest pier of the church (Fragment B). Yet, although this fragment constitutes part of the brick shell of the vaults, it does not include any elements from the exposed facing. The core of the vaults of Building D is yet another important source of evidence for reconstructing the monument. This is better understood if we consider that the missing bounding arches of the vaults formed the permanent mould of this core. Therefore, the shape of the core echoes the geometrical form of these missing arches. But the examination of the core is also interesting in its own right. Indeed, this core did not only constitute an important element of the elevation of the building; it also had an important structural role. It transmitted part of the thrusts of the broad arches to the piers below it. The significance of this component makes the study of its remains crucial for our understanding of the whole structure.

1. Analysis of Vault Fragments Due to the extensive dilapidation of its surviving fabric, Building D preserves very little of its original, main vaulted shell. The amorphous masses of brick and rubble masonry found on top of four of the five surviving piers mainly derive from the core of the vaults, and only include minor traces of the facings. Such exceptionally important traces, made entirely of solid brick masonry, are found on top of the southeast and southwest piers of 340 According to A. Choisy (1883, pp. 160–161) the remains of Building D betray “the tendency to reconcile roman plan [typologies] with oriental [vaulting] practices”. 341 Indeed, in A. Choisy (1883, fig. 177), the bays of the building are depicted as being square in plan, whereas they are in fact oblong, measuring 11.2x14.2m.

The Remains of the Southeast Pier The Southeast pier of the church preserves remains of both the core and the brick shell of the vaults it used to

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118. Sardis, Building D, southeast pier, elevation (drawing by Nikolaos Karydis, 2008).

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The Vaults of Building D at Sardis

119. Interpretive axonometric of the southeast pier. The extant remains are drawn in detail, whereas their reconstructed surroundings are shown with dashed lines (drawing by Nikolaos Karydis, 2008). support (vault fragment A) (fig. 118). The north and west sides of these remains appear to be curved. This curvature is especially apparent in the corner between these sides, which consists of 20 - 25 oversailing horizontal brick courses. Our photos, brought into scale and measured, suggest that the surface of each of the sides of this corner is clearly cylindrical. The springing course of both the north and south sides is recessed by at least 90cm in relation to the horizontal outline of the base of the pier, which is still visible, further down (fig. 119). These observations seem to suggest that this core was built behind the extrados of semi-cylindrical barrel vaults, (or semi-circular broad arches) which are now missing.

existing west side of the remains of the vault core would have originally stood a semi-cylindrical broad arch with a radius of circa 4.75 cm.343 With the similar method, displayed in figure 121, we arrive at the conclusion that next to the north side of the southeast pier would have stood another semi-cylindrical broad arch. The spacing of the piers indicates the wider span of this second arch. Its semi-circular tracing is suggested by the curvature of the north side of fragment A. The span and shape of this second arch lead us to conclude that the latter must have been higher than the first one. As we will see in the following paragraphs, this irregularity has been an integral part of the original design of the building, influencing significantly the form of its vaults.

The curvature of the existing faces of the core of the vaults can lead us to reconstruct the shape and size of the extrados of the arches that had originally stood against these faces.342 Figure 120 demonstrates that next to the

which will determine the shape and size of the missing supporting arches. 343 Given the semi-circular tracing of this vault, its height would have coincided with the half of the distance between the Southeast pier and the pier in its west. The surviving recess in the pier structure, created by the arch’s collapse, suggests that this arch would have been 90cm– 100cm thick. Its depth, betrayed by the plan of the pier, must have been 4.5m.

342 These sides rise up to a height of 2.4 meters each. The length of their curve must have represented not less than 25% of the total length of the extrados of the missing arches. We deem these remains to be adequate to allow us to trace with accuracy the shape of the rest of their curve,

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Early Byzantine Vaulted Construction in the West Coastal Plains and River Valleys of Asia Minor

120. Vault fragment A, reconstructed north elevation, superimposed on the photograph of the remains (drawing by Nikolaos Karydis, 2009).

121. Vault fragment A, reconstructed west elevation, superimposed on the photograph of the remains (drawing by Nikolaos Karydis, 2009).

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The Vaults of Building D at Sardis

122. Vault fragment A, detail of northwest corner showing remains of pendentive border.

Vault Fragment A

peculiar brick layout that does not seem to be typical of a pendentive. Indeed, what we see here seems to be a wedge-shape component made of the merging of two arches made of bricks laid radially. Although the bricks of these arches seem to interlock in the surviving fragment, there would surely come a point when these arches would become independent, following the arc of the extrados of the broad, supporting arches outlined above. We therefore come to the conclusion that this corner detail is not part of the pendentive itself, but an intermediate arched zone, serving as a structural transition between the main pendentive and its supporting arches.345

Continuing our survey of the top of the southeast pier, we come across a crucial detail. The northwest corner of fragment A is occupied by an element with a peculiar, distinctive construction (fig. 122). In the original structure, this element must have been located at the corner junction of the two broad arches. Unlike the rest of the fragment, which had been covered by the vault shell, this element, located between the arches, rather than behind them, must have been exposed to the viewer in the interior of the building. It should therefore be considered as part of the facing of the original vaulted shell. The excavation team at Sardis has long considered this construction detail to be part of a pendentive. As pendentive remains often suggest the former existence of spherical vaults, this element has been considered one of the most important indications of the original use of vaulting in the building.344 However, a closer examination of the structure of this element reveals a

This transitional arched border probably ensured the connection between the pendentive structure and the supporting arches. This has often been a problematic issue in Early Byzantine architecture. Indeed, in other Early Byzantine churches, such as St. Eirene, in the absence of similar transitional zones between the arches and the pendentives, the builders have had to painstakingly alter the tracing of the pendentive courses

344 Indeed, the term “pendentive” is used in the identification of the location of the fragment in the plan with the code number M-77B(C), found in the archives of the Sardis expedition. I would like to thank Ms. Kathy Kiefer, and the Archaeological Exploration of Sardis, for providing me with a copy of this document.

345

A. Choisy (1883, Pl. XVI, 3) has drawn these secondary arches and shown the way in which they converge and merge below the pendentive springing.

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Early Byzantine Vaulted Construction in the West Coastal Plains and River Valleys of Asia Minor so as to make them engage tangentially with the faces of the supporting arches.346 At Sardis, by using an intermediate arched zone between main arch and pendentive, the builders were able to create a face with the proper inclination for the masonry of the spherical pendentive to lean against it. It was this intermediate zone, or charfrein, that helped to inscribe a spherical pendentive within the space between the arches, and made it possible to avoid the recourse to irregular pendentive forms such as the ones observed in St. Eirene at Constantinople by W.S. George (1913). The Vault Core The lack of significant remains from the shell of the vaults, whose only vestiges are fragments A and B, seems to be puzzling given the abundant remains of the core of the vaults. This can be explained if we take into account the incoherence of the original vaulted structure and its possible role in the collapse of the building. Indeed, the vaulted shell, probably made of solid brick masonry, must have differed from its backing, consisting of rubble masonry reinforced with brick bands. The remains show that the bond between brick shell and rubble backing has been very weak. Indeed, the even, regular surface of the core of the vaults demonstrates the absence of interlocking “stitches” between shell and core. Therefore, it is very likely that at the time of the collapse of the roof, few parts of the fragmenting vaulted shell were anchored in the vault core. During the collapse of the building, the shell of the vaults was probably detached from the core leaving great parts of it on top of the piers.

123. Vault fragment A. View from the southeast with detail of external facing of rubble and brick masonry. pell-mell, between bricks. The rubble masonry bands, about 75cm high, contrast with the neat, regular appearance of the carefully formed facings of the vault shell and the brick reinforcement. The importance of this reinforcement in maintaining the coherence of a masonry structure that comprises an important amount of loosely bonded material has been noted in the context of our examination of rubble masonry walls.348 However, for the use of this reinforcement in vaults, yet another explanation can be given. Indeed, the incorporation of brick bands in the vaulting, characteristic of Roman Imperial vaulting practices, apart from compartmenting the mass of mortared rubble, would have helped to limit the flow of mortar during drying out, and so diminish the risk of settlement.349

In our study of the vault core, the top of the southeast pier is once again the focus of our attention, as it provides us with the better-preserved fragment of the vault backing. An extensive portion of the original façade is extant on the east side of this pier (fig. 123).347 Similar, but less well-preserved fragments of the façade are found in the south elevation of the southwest pier, and in the west elevation of the northwest pier. This façade consists of alternating bands of rubble masonry and brickwork. The face of each brickwork band is about 20cm high, consisting of three courses of brick. These bonding courses seem to penetrate in the masonry core, but it is not certain whether they maintain their form as they run through it. The current west and north sides of the southeast pier, which would have originally been covered by the shell of the vaults, suggest that, within the core, these bonding courses assume a more irregular character and a looser structure through the insertion of rubble,

The core of the vaults of Building D, surviving up to a height of circa 3.7m over the springing of the vaults, must have had an important impact on the original elevations of the building. Indeed, their height must have represented at least 2/3 of the overall height of the narrow arches. It seems, therefore, that the effect of these arches on the external appearance of the building would have been attenuated by the vault core masses rising next to them.350 The height given to the vault backing does not only betray design considerations related to the elevations of the monument, but structural considerations as well. The considerable mass of this core betrays its important role in counteracting the lateral thrusts of the transverse arches. In vaulted halls flanked by aisles, a part of these thrusts are counteracted by the secondary vaults of the aisles, strategically abutting the piers at the level of the

346 This tangential engagement was necessary for the efficient transmission of thrusts from the pendentives to the supporting arches. In order for such a connection detail to occur, the pendentive courses, which would have normally have the shape of circular arcs, would have to be given a variable curvature, which would have been more difficult to trace than a circular arc. See W. George (1913, pp. 41–42). 347 The well-formed, perfectly vertical masonry face, with its brick bands absolutely flush with the surrounding rubble masonry, are the main indications leading to the identification of this portion as part of the external face of the pier’s structure.

348

See Chapter 2, Section 2. See J. B. Ward-Perkins (1958, pp. 81–82). 350 These arches were not only surrounded by the vault core, but also blocked by walls, as the remains of spur walls on the base of most of the piers seem to suggest. 349

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The Vaults of Building D at Sardis ellipsoidal domes seem to have been quite rare in early Byzantine Architecture.352

springing of the main arches. On the other hand, in Building D, where there are no aisles, the weight of the arches’ backing is essential in shifting the direction of the thrusts from the horizontal to the vertical, as the latter are transmitted from the arches to the pier. The mass of what seems to be an inert filling mass is, in fact, very important for the stability of the whole structure.

The church of St. Eirene at Constantinople, as it appears in two 20th century surveys, seems to be one of the rare known instances of the use of elliptical arches in conjunction with the erection of an allegedly ellipsoidal dome over an oblong bay.353 Yet, as it has been shown above, these elliptical arches are not steep enough to equal the height of the wide semi-circular arches. Nor is it certain that all the courses of the dome follow elliptical patterns, as one would expect to find in a shallow ellipsoidal dome. Therefore, the use of elliptical or oval vaulted elements in the west bay of the nave of St. Eirene does not seem to fully resolve the issues of the adaptation of a pendentive dome to an oblong bay plan.354

2. Oblong Bays and Spherical Vaults The sides of the bays of Building D have a proportional relationship of almost 3:4. Such oblong bays may be regarded as an unusual base for the erection of a spherical vault. Indeed, both pendentive domes and full domes on pendentives are usually associated with square bay plans as opposed to rectangular ones like the one at Sardis. And yet, the analysis of the vault fragments of Building D attested the existence of pendentives, i.e. elements that would have most likely formed the base of a spherical vault. The resolution of this paradox will have a key role in the reconstruction of the monument’s original vaults.

The resolution of this problem in St. Eirene is found in the design of the central portion of the vault itself. Indeed, as we saw in our examination of the vaults of St. John,355 a pendentive dome, as the one in St. Eirene, is more easily adaptable to a rectangular bay than a hemispherical dome on pendentives.356 The particular structure and geometry of such a vault help to resolve the issue of the differing arch heights. Indeed, the pendentive courses join over the lower arch apexes until they reach the level of the apexes of the higher arches. This level coincides with the springing course of the shallow dome. The latter forms part of the same spherical surface as the pendentives, and therefore there is no visible transition from one element to the other (figs. 124, 125). This is the reason for the frequent early Byzantine use of such vaults in rectangular aisle bays.

After St. John at Ephesos, Building D at Sardis seems to constitute yet another instance of the construction of spherical vaults on a rectangular plan. In the case of St. John, the construction method in which this was achieved was discovered through the examination of numerous fragments. In the case of Sardis, the surviving fragments are not sufficient for this purpose. Here, it would be preferable to investigate the early Byzantine building methods with which a pendentive dome or a dome on pendentives can be built on an oblong plan, and then to examine which of these methods could have been used in Building D.

The pendentive domes in the four corners of the gallery of Hagia Sophia, which we examined in the previous chapter, are examples of such an adaptation to a rectangular plan.357 Both the dimensions and proportions of these corner bays are similar to the ones of the bays of Building D. Even though there are some differences between the two cases, in both of them a common problem has been dealt with: the adaptation of a spherical vault to a rectangular bay. This was achieved by choosing the form of a shallow dome with the same curvature as the pendentives, as opposed to a full, hemispherical dome. The shape of the nave bays, the pendentive remains, and the reconstruction of the missing arches at

A simple way to erect a dome over a rectangular bay would be to give it an elliptical shape, building it on an oval plan. Yet, this form cannot be combined with the use of semi-circular arches. In order for the crowns of the arches to have the same height, something necessary for the support of the base of the dome, either the narrow arches are given an elliptical shape, or their springing is elevated in order for their peaks to reach the level of the apexes of the wide arches. Although these geometrical manipulations seem profoundly simple and logical today, it is doubtful whether they were understood, or appreciated by early Byzantine builders.351 Indeed, elliptical arches and

352

Indeed, the general survey of Early Byzantine architecture by Ch. Bouras (1993, p. 116) shows that the semicircular arch form was never abandoned in favour of the elliptical one. 353 According to W. George (1913, p. 41), in the west bay of St. Eirene, “the bounding arches are of unequal span but of equal height, the wider arches being semicircular, and the narrower roughly elliptical”. 354 The photographs of the west dome of St. Eirene, published in C. Mango (1978, fig. 126) and R. Mainstone (1988, fig. 97) suggest that both the section drawings of U. Peschlow (1977, pl. 3) and W. S. George (1913, p. 41), in which the narrow, longitudinal arches have the same height as the wide, transverse arches, are mistaken. 355 See Chapter 3, Section 2. 356 For the geometrical definition of a pendentive dome see S. ûurþiü (1992, p. 28). 357 According to R. Mainstone (1988, pp. 81–83), the bricks of these pendentive domes were laid in circumferential rings, according to a manner of construction similar to the one of St. Eirene.

351 The reluctance of the builders of Justinian’s Hagia Sophia to give the longitudinal arches of a rectangular bay an elliptical plan has been noted by Mainstone (1988, p. 190) in his survey of the aisle vaults of the corner bays of the great church. He states: “in the sixteenth and seventeenth centuries in the west, the arches over these spans would probably have been made elliptical in profile. But such was the preference for the semicircular profile [in Byzantium] that they, too were made semicircular…”

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Early Byzantine Vaulted Construction in the West Coastal Plains and River Valleys of Asia Minor Sardis seem to indicate that the vaulted pattern of Building D was similar to the one employed in Hagia Sophia’s gallery (see fig. 104).

3. Reconstruction of the Vaulted Structure The examination of the vaulted fragments, and the interpretation of their former role with the help of comparable examples elsewhere lead us to start unveiling the original form of the missing vaults and arches of Building D.358 The order in which the architectural features are presented reflects the sequence in which the form of the original vaults can be gradually reconstructed, often with each vaulting component supplying information about the one next to it. Thus, the presentation of the vaulted structure starts from the bounding arches and ends with the central portion of the vaulted roof. Broad Arches Even though there are no remains of the main arches that spanned the distance between the main piers and carried the vaults, some aspects of their geometry and layout can be revealed through the examination of the surviving piers (fig. 119). Indeed, the profiles of these piers and, in particular, the outline of the projecting pilasters are indicative of the section of the arches. The span of the arches can be deduced from the spacing of the piers, while their semi-cylindrical tracing is reflected in the curvature of the facing of the vault core.

124. Reconstructed, cut-away axonometric of southeast pier, showing supporting arches, pendentive border, and quarter of domical vault (drawing by N. Karydis, 2009). vertical faces, at least 90 cm high, and their important soffit widths, ranging from 3.5m to 4.75m, would have been exceptionally prominent in the interior of the building.361

The spacing of the piers indicates that the latter carried broad arches of two different spans. The three transverse arches were both wider and taller than the four longitudinal ones, parallel to the main axis of the church. As the re-entrant angles of the pier profiles seem to indicate, the arch structures were completely independent, without any kind of merging at the corner of their springing.359 These same profiles show that these arches must have had an important depth, which represented almost 1/12th of their span.360 Their exposed

Although the outline of the arches can be reconstructed, their structural fabric is still obscure. It is very likely that they were mainly made of bricks laid radially upon timber formwork, the standard method, not only in early Byzantine Asia Minor, but in Constantinople as well.362 In the absence of surviving fragments, it is difficult to decide whether these arches consisted of a compact, solid brick and mortar mass, or if they were composed of multiple, concentric rings of radial bricks. Still, an examination of comparable examples in the broader context of late Antique western Asia Minor seems to suggest that the building tradition within which Building D was created seems to have privileged the second type, making the existence of arches divided into two, or three concentric rings plausible.363

358 In my reconstruction of the vaulted fabric of Building D, I have relied to a significant extent on information drawn from earlier reconstruction drawings, kindly given to me by the team of the Archaeological Exploration of Sardis. This set of drawings includes a plan of the remains of Building D, (M-77A) a “restored plan” (M-77B) and a parallel between “existing and reconstructed sections” of the building (M-77C). Even though this graphic reconstruction includes drawings that improve our knowledge of the original form of Building D, it can also be misleading in certain respects. For instance, the reconstructed section of the building seems to be problematic as far as the depiction of the vaults is concerned. In this schematic section, the apexes of the wide, transverse arches are shown to be in a lower level than the apexes of the narrow, longitudinal arches, something impossible. 359 This type of construction distinguishes the arches of Building D from the ones of St. John at Ephesos, and Hagia Sophia at Constantinople. 360 Similar depths are found in late Roman arches, such as the ones of Basilica Nova, whose span is two times the span of the arches of Building D. In both Basilica Nova, and Hagia Sophia, the main broad arches have an arch-depth of almost 1/20 of the span. See R. Mainstone

(1988, pp. 78, 169). For an outline of the structural system of Basilica Nova, see G. Pelliccioni (1986, pp. 26–31, figs. 9, 10). 361 For a similar observation concerning the visual impact of the arches of St. John the Theologian at Philadelphia, see H. Buchwald (1981, p. 316). 362 Indeed, most early Byzantine arches in western Asia Minor are constructed with bricks laid radially, with the exception of limited cases where the lower courses consist of horizontal bricks corbelling out. For a general survey of arch construction in early Byzantine Constantinople, see J. B. Ward-Perkins (1958, p. 58). 363 Examining late Antique, or early Byzantine buildings in Sardis and its vicinity, we find examples of both arch types. A characteristic

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The Vaults of Building D at Sardis

125. Sardis, Building D, reconstructed axonometric. Notice how the domical vaults adapt harmonically to the differing heights of their supporting arches (drawing by Nikolaos Karydis, 2009). Pendentives The arches of Building D were not provided with sloping faces (skewbacks) on which a pendentive structure with a spherical surface could lean. Vault fragment A shows that the vaults did not rest directly on the arches. There was a transitional zone between them (fig. 124). This zone was built with a single layer of bricks forming secondary arches, overlying the inner part of the extrados of the main arches. The lower part of these arches, which survives up to a height of 2.5 m above the springing,

consisted of horizontal courses of brick, while the upper part had been probably built with radial bricks. At the edge of these secondary arches, the bricks were tilted by almost 45º, so as to form a sloping bed upon which the spherical pendentive structure could be built. At the corners of convergence between transverse and longitudinal arches, the secondary arches merged into wedge-shaped components, one of which can still be observed on the northwest corner of the southeast pier. In it, we realize that the bricks of the two arches interlock, and gradually become smaller as this wedge-shaped component tapers downwards.

example of arches with a solid structure occurs in St. John at Philadelphia. On the other hand, western Asia Minor preserves numerous cases of arches consisting of two or more concentric rings. The remains of the Harbour Baths at Ephesos and the Gymnasium at Sardis are two examples of late antique sites where such composite arches are found. In hall BSH of the Gymnasium at Sardis, there are semi-circular arches consisting of two rings. Yet, these rings do not have the same thickness. The inner ring is 55cm thick while the outer ring is only 35cm. The total arch thickness is 90cm, equal to the depth of the arches of Building D. A similar structure may have been employed in Building D. Indeed, Chapter 3, II, 6, verifies the existence of similar forms in the 6th century. For the use of composite arches in the Harbour Baths at Ephesos, compared with similar structures in 6th century Constantinople, see F. W. Deichmann (1956, pp. 84–95, pl. 2).

The survival of a significant part of this pendentive border, which, unlike the arches and pendentives, has withstood the passage of time safely embedded in the vault core, has a crucial importance for the reconstruction of the vaults of Building D. We have already used its fragments as evidence for the nature of the main arches that had stood immediately below it. In the following paragraphs these remains will contribute in the reconstruction of the main vaults of the building.

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Early Byzantine Vaulted Construction in the West Coastal Plains and River Valleys of Asia Minor

Primary Vaults The nave of Building D must have been covered by pendentive domes, as opposed to domes on pendentives (fig. 125). A series of reasons have led us to this hypothesis. Indeed, the inscription of hemispherical domes in oblong bays has been shown to be problematic.364 The use of domes built on oval plans to overcome this problem should also be excluded, as being not only rare in early Byzantine architecture, but also incompatible with the rectangular layout of the bays of Building D and the form of its main arches. Indeed, the height difference between the apexes of the longitudinal and transverse arches of each bay would have made it impossible for these arches to support the horizontal springing course of a dome directly. Finally, the sloping bed of the pendentive border overlying the main arches is indicative of a vault with a continuous spherical surface, which had not been limited to the space of the pendentives, but extended over their peaks as well. Such a vault, in which there is no visible distinction between the intrados of the calotte and the pendentives could only have been a pendentive dome. The varying margins of such a spherical vault would have been the key to its adaptation to the oblong bays, and dissimilar arches of Building D. The reconstructed plan and arch elevations of Building D can lead to a safe reconstruction of the geometric structure of the pendentive domes that covered the nave.365 Although the form of these vaults has been established, in the absence of fragments of their main shell, the way in which they were built is still uncertain. Given the considerable variety of early Byzantine pendentive dome structures, it is difficult to determine the exact method employed in Building D. It is also difficult to establish whether these vaults dispensed with centering or not. Nevertheless, the main vaults of Building D, together with the ones of the nave of St. John serve to remind us that early Byzantine builders considered the pendentive dome as worthy of covering the central spaces of their churches as the dome on pendentives. They also demonstrate that cases of shallow domes on pendentives, such as the first dome of Hagia Sophia, or the west dome of St. Eirene were not unique to Constantinople, but reflected a similar development in western Asia Minor.

364

See Chapter 3, Section 2. The original geometric structure of these pendentive domes can be drawn on the basis of the reconstructed plan of the building, and the reconstructed elevations of its main arches. Indeed, in a pendentive dome, both the pendentives and the shallow dome on the top form part of a continuous spherical surface, and therefore have the same radius. As A. Choisy (1883, p. 99) has shown, this radius coincides with the half of the diagonal of the plan of the bay. By measuring this diagonal we can trace both the transverse and the longitudinal section of the intrados of the dome. 365

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Chapter 5 The Vaults of St. John the Theologian at Philadelphia (Alaúehir)

126. Philadelphia, St. John, northeast pier. Detail of arch and pendentive remains.

1. Introduction The preservation of numerous vault fragments within the remains of St. John at Philadelphia compensates us for the absence of documentary evidence for the original form of the monument. In St. John at Ephesos, the form of the pendentives was reconstructed on the basis of small, scattered fragments; at Sardis, the shape of the main arches, entirely missing, could only be found through the study of their surviving backing. In St. John at Philadelphia, on the other hand, great portions of the arches and the pendentives not only survive, but also remain undisturbed in their original context (fig. 126). The completeness of this structure gives us the unique opportunity to study in detail those constructional characteristics that seem to distinguish vaulting practice in west Asia Minor from other early Byzantine building traditions.

(detailed description of vault remains, an interesting reconstruction attempt, useful comments on architectural character), while also registering a few limitations.368 My own survey of the monument builds upon this work, hoping to offer an accurate representation of vault fragments, and to identify details in their fabric, which can serve to reconstruct the original vaults of the church. The present survey is probably the first one to benefit from the improvement of the site’s accessibility (after the removal of contemporary structures from it), and from the partial excavation carried out around the southwest and northeast piers.369 This excavation has revealed to me parts of the monument which had been unknown previously.

Our present knowledge of St. John is indebted to the work that Hans Buchwald has devoted to it, and published in 1981.366 The first steps towards the study of the vaults of St. John had been made a century earlier, by A. Choisy, whose reconstructed plan of the monument was accompanied by a remarkably accurate axonometric of one of the vault remains. The French author also noted the similarity of the vaults at Philadelphia with the ones of Building D, at Sardis, examples that he classified within the same early current of Byzantine vaulting development.367 This late 19th century publication must have had an important influence on H. Buchwald, who went on to offer us a more scholarly and accurate survey of the monument, based on a thorough description of its visible vault remains.

2. Analysis of Vault Fragments The imposing remnants of the vaults are found on top of the two north piers. Observing the form of vault fragment A, on top of the northeast pier (fig. 127), and vault fragment B, on top of the northwest pier (fig. 128), one easily distinguishes the springs of the major arches.370 Within these remains, there are also three pendentive fragments, a substantial one in the northeast pier, and two minor, but equally important ones in the northwest pier (fig. 129). The north elevations of both vault fragments

368

These limits lie in the depiction of vault fragments, and the slightly inconsistent reconstruction drawings. Indeed, in both the elevations and the schematic section of the monument published by H. Buchwald (1981, pl. II, figs. 1–3) the total height of the vault fragments on top of the piers (shown to reach 7.8 m) seems to be slightly exaggerated, compared to my own measurements. Also, in the reconstructed section of the building, the transverse arches are shown to be higher than the longitudinal ones, something which seems to be in conflict with their equal diameters and the fact that both seem to have the same shape and to spring from the same level. 369 See R. Meriç (1990, pp. 227–236). 370 E. Curtius (1873, p. 96), in what is probably the first description of the ruins of St. John at Philadelphia, emphasized the fact that the piers had been originally linked with brick arches. According to this author: “sie waren durch große Ziegelsteinbögen verbunden, welche indessen eingestürzt sind”.

It was this last description that guided my own, on site study of the monument in the spring of 2007. Throughout this study, I verified the merits of H. Buchwald’s survey 366 See H. Buchwald (1981, p. 315) for a thorough survey of the remains of St. John, accompanied by a reconstruction, and an attempt to interpret the monument within the context of early Byzantine architecture. This was the first detailed survey of the monument, brief descriptions of which had been previously included in E. Curtius (1873, p. 95), and A. Choisy (1883). 367 See A. Choisy (1883, pp. 160–161, fig. 176, pl. XVI, 1).

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127. Philadelphia. St. John. View of northeast pier from the west with vault fragment A on the top.

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The Vaults of St. John the Theologian at Philadelphia (Alaúehir)

128. View of northwest pier from the south, showing vault fragment B. Note the pendentive remains (left).

conserve large portions of their external facing intact.371 Arches, pendentives and facing enclose enormous inert masonry masses, which constitute the vault core, which, in this particular instance, is also the vault backing. The northwest pier of St. John gives us the opportunity to observe the stratification of these cores, revealing a structure much more complex than its description as “mortared rubble” seems to imply.372 Vault fragment A (northeast pier) is similar to vault fragment B (northwest pier).373 A separate examination of the two fragments would run the risk of including repetitions. For this reason, the following survey is organized in sections dealing with remains of vaulting components: arches, pendentives, core, and external facing. Each of these sections is based on information drawn from both fragments.

371 In the following paragraphs we will examine the degree to which theses facings can lead us to reconstruct the original façade of the building. 372 See H. Buchwald (1981, p. 316). 373 Indeed, according to H. Buchwald (1981, p. 306), “the remnants of vaulting on the E, S, and W sides of the upper part of the NW pier correspond closely with those of the NE pier”.

129. Northwest pier. Detail of pendentive fragment.

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Early Byzantine Vaulted Construction in the West Coastal Plains and River Valleys of Asia Minor

130. Reconstructed north elevation of northeast pier and its adjoining arch. The corresponding photograph of the remains has been brought to scale and used as a background (drawing by Nikolaos Karydis, 2009). of brick.374 Thus, the springing course of the arches is elevated by roughly 100cm over the pier cornice.

Broad Arch Fragments The remains of the broad arches, which originally interconnected the piers of the building and supported the central portion of the vaults, first demand notice. The better preserved of these arches is the one between the two north piers. Of this broad arch, both springs survive, representing roughly half of its original volume. The following paragraphs will focus on these specific remains, for they give the best opportunity to investigate the techniques employed in the construction of the arches of St. John. The composite form of the north arch (consisting of a wide inner arch and a narrower outer arch) has already been described. Less is known about its exact shape and structural fabric.

Figures 130 and 131 demonstrate that the profile of the west springing of the arch approximately matches with a semi-circular outline (shown with dashed line) that is raised 1m above the level of the top of the cornice.375 A closer investigation of the remains, however, reveals that, in fact, the arch has a series of irregularities. Its curvature is not stable, as we would expect from a semi-circular arch, but varies. Yet, in spite of these variations, the height of the original arch had probably been equal to the half of its span.376 We are therefore dealing with an arch 374 H. Buchwald (1981, p. 304) states: “the lowest course of the arches is constructed of ashlar”. However, the ashlar blocks are part of the piers, and not part of the arches. 375 According to Ch. Bouras (1993, p. 115) the elevation of the arches’ springing is a regular feature in the age of Justinian. The author explains the reasons for the adoption of this arch type both from a structural and an aesthetic point of view. 376 Indeed, a surviving part of the west springing of the arch (starting from the level of +0.75m over the springs (±0.00), and reaching the one of +3.65m) has a circular outline with a radius of almost 8.50m, whereas in other parts there is a sudden adjustment, with the curvature augmenting and the radius diminishing to less than 4.00m. It is very likely that the purpose of these adjustments is to limit the degree to

Contrary to standard practice, this arch does not seem to spring directly from the top of the cornice crowning the ashlar masonry piers, not even from the top of the ashlar blocks laid directly on top of this cornice. In fact, the vertical facings of the piers extend over the top of the cornice, first with a course of ashlar blocks (with occasional gaps filled with 8–9 courses of brick masonry), and, above that point, with at least two courses

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The Vaults of St. John the Theologian at Philadelphia (Alaúehir)

131. Reconstructed north elevation of northwest pier and its adjoining arch superimposed on photograph of the remains, as in fig. 130 (drawing by Nikolaos Karydis, 2009). of unstable curvature, which approximates in form to a semi-circular arch.

This manner of building, betraying the reluctance of the builders to allow the beds of the brick courses to become steeply inclined, seems to indicate that the feet of the arches were built without centering.378 It was possibly the absence of such a system of temporary support that led to what W. George (1913, p. 39) had characterised a “freehand” method of arch construction, which produced “non-geometrical arch forms”.

This arch form seems to reflect constructive necessities as opposed to geometrical or aesthetic considerations.377 The examination of the structural fabric of the arch seems to corroborate this hypothesis. As figure 132 demonstrates, up to a level of almost +2.00m above the pier cornice, the arch was built with over-sailing brick courses on roughly horizontal beds. Above this part, and until the level of +4.00m over the cornice, the beds of the brick courses, having assumed an inclination of 13º, are kept almost parallel and somewhat less than normal to the curve of the arch. These parallel bricks correspond to a portion of the arch that markedly deviates from the semi-circular outline on which the entire structure seems to be based.

However, this explanation seems to be in conflict with the existence of a series of cavities at the feet of the arches (fig. 133).379 Similar cavities, observed at Hagia Sophia and St. Eirene at Constantinople, have been considered as indications of the use of flying centers in the construction of arches and vaults.380 Yet, one could also see them as traces of the use of tie beams, meant to

378

which the arch deviates from the semicircular outline, and to ensure that its total height roughly equals the half of its span. 377 W. George (1913, p. 39) has interpreted the “non–geometrical” form of some of the vaults of St. Eirene in a similar way. An alternative interpretation of this geometrically irregular arch structure would be to see it as a result of the gradual deformation of what had originally been a semi-circular arch. A similar deformation has been observed at Hagia Sophia by R. Mainstone (1988, p. 203, fig. 232).

Indeed, according to W. S. George (1913, p. 41), in his survey of the use of vaulting in St. Eirene, “by keeping the beds of the [vault’s] courses as nearly horizontal as possible, [part of] the vault could be built without centering.” Cf. A. Choisy (1883, p. 62). 379 These holes, measuring approximately 30x30cm, are located in the arch soffits just below the level of the springing, as well as in the faces of the arches, at a slightly higher level. 380 See R. Mainstone (1988, p. 202).

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132. Reconstructed south elevation of northwest pier, superimposed on photograph of the remains as in the two previous figures (drawing by Nikolaos Karydis, 2009). ensure the coherence of the structure until the mortar in it dries and develops its full strength.381

Pendentive Fragments The pendentive of vault fragment A, springing between the two arches converging to the northeast pier of St. John is among the most impressive and rare finds of our research. This fragment not only survives in its original location, but also represents an extensive portion – almost half – of the original pendentive fabric. Its study is essential for the determination of the geometry of St. John’s pendentives. Ironically, the good preservation of this component does not facilitate the observation of its structure. Only the facing is revealed, with no section or edge helping to establish the mode of construction. To investigate the latter, we will turn to the two pendentive fragments in the south corners of vault fragment B, more modest in size, whose disintegration makes observations concerning the construction of pendentives possible.

The greatest part of the arch remains is built with exceptionally large bricks, measuring 70x70cm, and laid with their vertical joints staggered. The considerable thickness of the arches (approximately 1.00m), must have been necessary to allow them to reach the span of 12.20m, the distance between neighbouring piers. The arch thickness/span ratio of 1/12 observable in St. John is similar to the one of the arches of Building D, at Sardis. The dimensions of these arches, imposing even today, would have given them a certain prominence among the elements composing the vaulted ceiling of the church.

381 The role of these timber tie beams in the consolidation of masonry structures during the initial stage of their construction, when the latter are subject to settlement due to the drying out of mortar, has been explained by A. Choisy (1883, pp. 115–116). According to the French author, “il est peu d’édifices du bas Empire qui ne soient ainsi consolidés dans toutes leurs parties par des cadres en charpente plus ou moins apparents, habituellement noyés dans l’épaisseur de leurs massifs”. Recently, R. Ousterhout (1999, p. 211) revisited the same subject, noting that “wooden beams created a series of tension rings that secured the building against deformation”.

The pendentives of St. John seem to be structurally independent from the supporting arches, in accordance to standard early Byzantine practice. Yet, unlike the pendentives we examined at Ephesos, and Sardis, the ones at Philadelphia spring from the extrados rather than the face of the supporting arches. This is confirmed by vault fragment B. The partial collapse of the face of two

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The Vaults of St. John the Theologian at Philadelphia (Alaúehir)

133. Interpretive axonometric of northwest pier. Reconstructed parts are shown in dashed outline. Note the use of ashlar and brick masonry reinforcement in the core of the vaults, and the fact that the two pendentives spring from the extrados of the supporting arches (drawing by Nikolaos Karydis, 2009).

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arches within this fragment has revealed that the pendentives have a face that lies against the extrados of the arch. This detail is crucial for the reconstruction of the central vaults of the monument (fig. 133). The dilapidation of the pendentive in the southeast corner of fragment B reveals the manner in which it was constructed. Its lower 15 courses are laid on horizontal beds. Above this level and up until its present apex, the pendentive is formed by parallel courses, inclined inwards by circa 13º, the same pitch as the one of the courses of the arch next to it (figs. 133, 134).382 The same detail within vault fragment B indicates that the pendentive shell was approximately 70 cm thick. Its section presents an alternation of single, large bricks measuring 70x70 cm and pairs of half-size bricks, measuring 35x70 cm. It is difficult to establish the exact shape of the pendentives. The examination of the pendentive within vault fragment A from a distance suggests that it approximates the shape of a spherical triangle (fig. 127).383 However, a closer investigation shows that its surface is not spherical. Indeed, the plans of its upper brick courses do not have a stable curvature, as one would expect in a spherical pendentive, but are crooked in many points (fig. 135). The bends in the plan-curves of the pendentive probably resulted from adjustments made to resolve the problem of the connection between the bricks at the edges of the pendentive and the extrados of the supporting arches (figs. 136, 137).384 They allowed the courses of the pendentive to become roughly tangential to the faces of the supporting arches. One of the by-products of these adjustments was the irregular shape of the pendentive surface.385

134. View of vault fragment B, showing pendentive detail. The broken surface of the vault shell reveals the joint between the pendentive and the extrados of the supporting arch.

The existence of a large cavity (roughly 30x30cm) in vault fragment A shows that a diagonal timber beam had been embedded in the shell of the pendentive, at a level of approximately +4.00 m above its springing (fig. 126). This beam could have served as a tie beam during construction and until the mortar gains its complete strength. Alternatively, it could have supported a flying center used to construct the pendentives. The flat setting of the bricks, indicative of vaulting techniques that make only limited use of centering,386 seems to support the first hypothesis, without, however, totally excluding the second one.

382 This same manner of construction, “with bricks laid not quite radially in relation to the centers of curvature, but slightly flatter”, is also found at the dome of Hagia Sophia. See R. Mainstone (1988, p. 80). 383 Spherical Triangle: A triangular segment of a sphere 384 This problem must have been inherent in a structure that lacks transitional components between supporting arches and pendentives, similar to the ones found at Sardis. 385 Similar methods of pendentive construction have been observed both at St. Eirene and Hagia Sophia, at Constantinople. See A. Choisy (1883, pp. 90–94), and W. S. George (1913, pp. 41, 44). 386 For the use of such a technique at Hagia Sophia, see R. Mainstone (1988, p. 209).

135. Northeast pier. Vault fragment A. Detail of pendentive on the southwest corner of the fragment.

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136. Diagram illustrating the problematic connection between the arches springing from the northwest pier and a hypothetical pendentive with a precise, spherical shape (drawing by Nikolaos Karydis, 2009).

137. Reconstructed plan of the pendentive on top of northwest pier. Note how the irregularities in the surface of the pendentive improve the contact with the bounding arches (drawing by Nikolaos Karydis, 2009).

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Early Byzantine Vaulted Construction in the West Coastal Plains and River Valleys of Asia Minor The Vault Core The shell of the vaults of St. John at Philadelphia has a very different structure from the one used in their core.387 This core has an enormous volume, which makes it the most sizeable component of the vault fragments found on site.388 However, the study of its structure has been relatively neglected by previous research on the monument. Earlier publications tend to focus on the vault shell, and only give limited attention to what proves to be an important structural element, whose role in the counteraction of the lateral thrusts of the vaults should not be neglected.389 The claim that the core of the vaults was part of a “continuous zone of mortared rubble”390 does not correspond with the evidence offered by vault fragment B. The dilapidation of the shell of this fragment reveals an important part of its core. The latter, instead of being made entirely of mortared rubble, also includes at least one reinforcing band at a level of approximately 3.5 m above the pier cornice (figs. 132, 134). This band consists of four ashlar block courses with brick courses between them. This composite band, at least 85 cm thick, probably runs through the entire vault core. We cannot exclude that similar bands occurred repetitively within the core compartmenting the loose mass of mortared rubble. The structure of the vault backing at St. John seems to be slightly different from the one studied at Building D, at Sardis. Yet, in both these cases, the construction principle is the same, involving the use of mortar rubble in conjunction with reinforcing bands. It is only the construction of this reinforcement that distinguishes the two cases: at Philadelphia, an alternation of single brick and ashlar masonry courses replaces the solid brick masonry used at Sardis.

138. Northeast pier, view from the southeast, showing remains of external pier facing. The external faces of the vault fragments preserve the remains of large blind arches, which consist of two rings, and are recessed twice. Each ring is built with rectangular bricks (measuring 35 x 70 x 4 cm) lain radially. The arch springs are elevated by at least 2.50m over the level of the (internal) pier cornice, and rest on pilasters. The faces of the arches seem to project by at least 60 cm beyond the actual vertical face of the piers below (fig. 138).391 This suggests that the external facing of these piers was originally concealed by an outer wall, which does no longer survive.392

The Remains of the External Vault Facing The survival of significant remains of the external facing of the vault cores in St. John should be seen as a fortunate exception within a group of monuments in most of which few parts of the original facing survive. These remains offer important information about the north facing of the vaults and give us a rare opportunity to investigate the articulation of the elevations.

The facing of the vaults also includes remains of the wall between the arches.393 Spandrels and arches must have been separated by an arched zone of bricks laid with their main surface touching the extrados of the blind arches. In the north elevation, the external faces of the spandrels, flush with the outer rings of the blind arches, project by at least 60cm beyond the face of the barrel vaults that span

387 These vaults differ in that point from the vaults of St. John at Ephesos. 388 The account of E. Curtius (1873, p. 95) refers to the “colossal” size of the piers, and particularly stresses their large footprint. Indeed, the volume of each surviving vault fragment could be compared to the one of a two-storey building with a 7x6m footprint. 389 Indeed, A. Choisy (1883, p. 160), avoids any reference to the structure of the vault backing. H. Buchwald (1981, p. 316) describes this core rather summarily as “mortared rubble, (…) packed (…) behind the brick shell of the vaulting and the brick façade”. Yet, the same author recognizes that “the major part of the loads and stresses developed by the vaults was introduced into the massive mortared rubble core of the pier”. 390 H. Buchwald (1981, p. 316).

391

The biggest projection occurs in the east elevation of the northeast pier, where the facing of the vaults lies about 1.00m east of the face of the pier below it. 392 The excavations published in R. Meriç (1990, pp. 227–236), confirm this. It is very likely that the surviving vault facing was part of this wall. The surviving facing would not have survived the collapse of the wall below it had it not been fixed firmly in some way to the vault core behind it. 393 Spandrel remains are found east of the north blind arch on top of the northeast pier, and west of the north blind arch on top of the northwest pier.

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The Vaults of St. John the Theologian at Philadelphia (Alaúehir) the distance between the piers (figs. 130 and 131).394 These observations indicate that the surviving blind arches must have formed part of a continuous wall, which enveloped the vault cores extending sideways in front of the outer face of the barrel vaults of the church. The same independence between the elements of the primary structural system (piers, major arches) and the outer walls occurs in St. Eirene and in Hagia Sophia at Constantinople.395

between pendentive domes and hemispherical vaults on pendentives. Having accepted that the existence of both forms is possible, we can move on to discuss the impact of the adoption of each of these vault types on the architectural character of the building. Arches and Pendentives As we have seen, arches and pendentives sprang 1.00m above the pier cornice. It was also demonstrated that the arches deviated from the customary semi-cylindrical tracing to the same subtle degree as the surface of the pendentives departs from its expected spherical shape. However, the impact of these distortions on the appearance of these vault elements themselves must have been minimal, as they can hardly be distinguished from a distance: in spite of their irregularities the broad arches must have seemed semi-cylindrical, and the surface of the pendentives must have strongly resembled the one of a spherical triangle.

The remains of the east elevation probably preserve the only instance where the face of an internal barrel vault interrupts the outer wall (fig. 138). This barrel vault extends out with its vertical face being flush with the faces of the blind arches flanking it. Two features of the east elevation will prove to be essential for the reconstruction of the entire vault facing. First, we should note the existence of an unexpected ornamental element: the remains of a dogtooth frieze overlie the extrados of the barrel vault. 396 Secondly, this elevation clearly shows that the springs of the barrel vault and the blind arches merged externally.

On the other hand, the adoption of an irregular geometry is very likely to have had an effect on the appearance of the domes. Indeed, given the plan-curvature of the pendentive courses, the curve formed by their tops would not have been a true circle, but rather a ring with varying curvature. In case the pendentives carried a hemispherical dome, this ring would be noticeable from the interior of the church, and the irregularity of its shape would not have been easily dissimulated. However, this irregular geometry does not seem to have influenced the architectural character of the monument in a significant way. Although similar irregularities occur in a wide number of Byzantine vaulted monuments, ranging from Hagia Sophia to St. Mark in Venice, seldom do researchers refer to them.398 Their existence may indicate that, for early Byzantine architects, methods destined to facilitate the construction procedure were more important than the faithfulness to the theoretical, geometric basis of vaulting components.399 St. John at Philadelphia, probably made by builders who interpreted the geometrical forms of vaulting elements freely, were destined to be used by a public concerned more about the symbolism of these elements than about the accuracy of their realisation.

With the exception of the external face of the east barrel vault, all the other elements constituting the outer facing of the vault zone (recesses, pilasters, blind arches) seem to form part of an external skin, which conceals the inner vault shell. The elevations of the building were probably regarded as aesthetically independent architectural entities, and their structure reflects that.397

3. Reconstruction of the Vaulted Structure St. John at Philadelphia represents the only instance in west Asia Minor where the original vaults can be reconstructed on the basis of fragments that remain in their original location. The extent and preservation of these fragments allow us to extend our reconstruction to aspects of the vault structure, which, in other monuments remain obscure. Only at Philadelphia are we able to establish with accuracy the original form and structure of pendentives, as well as to make hypotheses about the nature of the external facing of the vaults, and its role in the elevation of the building. On the other hand, in the absence of dome fragments, the exact original form of the upper portions of the vaults cannot easily be determined. In reconstructing this part, we are faced with the dilemma

The Facing of the Vaults and the Reconstruction of the Elevations The existence of numerous architectural details such as blind arcades with double setbacks, pilasters with niches, and dogtooth friezes betray that the elevations of St. John had a degree of sophistication, which seems to be seldom

394

I use the term barrel vault, as opposed to broad arch, in order to avoid confusion between the internal broad arches between the piers, and the blind arches that form parts of the pier elevation. In other parts of the book the use of the term broad arch is preferable. 395 W. S. George, (1913, p. 44) claims that, in St. Eirene, the “outer wall (…) was built independently of the barrel vaults”. R. Mainstone (1988, p. 81) notes that, in Hagia Sophia, “the outer walls pass by the faces of the piers without interruption, and, apparently, without any bond…” 396 Dogtooth frieze: a frieze made of bricks arranged to form a saw-tooth band. R. Krautheimer (1986, p. 353) considers such friezes a typical element of Middle Byzantine architecture. 397 To what extent these facing elements were part of the original building programme of the church will be discussed once this facing is reconstructed, in a following part of this chapter.

398

See R. Mainstone (1988, pp. 91, 209, fig. 107). This argument seems to be supported by the claim that “in Byzantium, the essential role of the Architect was to build” (Dom H. Leclercq et al., 1903–1953, pp. 2763–2769). On the other hand, G. Downey, based on the 4th century treatise of Pappus of Alexandria, has proved that geometry, and geometrical methods played an important, if not a major role in Byzantine design and construction. See G. Downey (1948, p. 117). 399

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139. Philadelphia, St. John, reconstructed axonometric showing the north elevation of the church, including the facing of the piers and a hypothetical representation of the missing apse and lunette walls (drawing by N. Karydis, 2009). encountered in early Byzantine monuments.400 The complex nature of this elevation makes its reconstruction difficult. On the other hand, the sheer quantity of remains makes this the best opportunity to examine aspects of early Byzantine building in west Asia Minor that have rarely been studied.

remains denote that the blind arches carried a brick masonry wall with its face flush with the face of the outer rings of the blind arches. These fragments constitute yet another confirmation of H. Buchwald’s hypothesis that this wall was next to the outer face of the barrel vaults connecting the piers, rather than below it.401

The impact of the enormous masses of the vault cores on the external appearance of the building must have been an important issue for the architects of St. John. It is very possible that they took measures to articulate these colossal elevations. The vault cores were faced externally with blind arches recessed twice. The springs of these arches were raised on pilasters with a re-entrant profile. The blind arches span the entire width of the piers. Their tops were covered by a single layer of tiles, laid flat upon the surface of the arch extrados. A series of spandrel

We know very little about the form of the wall that closed the barrel vaults on the exterior. It is not certain whether blind arches occurred only over the main piers, or formed part of an arcade, which ran along the entire upper tier of the elevations of the church. In resolving these problems, we should take into account that, according to general Byzantine architectural practice, the profiles of internal barrel vaults are almost always echoed in some way in the corresponding part of the elevation.402 The projection 401

See H. Buchwald (1981, p. 313). Typical examples of this tendency occur in St. Eirene at Constantinople (6th century), the church of the Koimesis at Nicaea (probably early 8th century), the Myrelaion church at Constantinople (10th century), and St. Mary of the Coppersmiths at Thessaloniki (11th century). See R. Krautheimer (1986, pp. 250, 290, 356, 374). W. S. George, (1913, p. 44) shows that, in St. Eirene, the curvature of the 402

400

Indeed, according to Cyril Mango (1978, p. 115), elevations characterized by the recession of planes, and including elements such as blind arcades represent new, middle Byzantine trends, which are only generalized during the 11th century. The sculptural effect created “contrasts with the practice of the Early Byzantine period.”

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The Vaults of St. John the Theologian at Philadelphia (Alaúehir) likely to have made the junction of the two elevations in the northeast corner very difficult to design, and to build. The pilaster in the corner of the northeast pier is indicative of the resolution adopted by the architects in order to overcome this problem.

of the face of the east barrel vault so that it becomes visible in the east elevation, attested by the surviving structure, shows that St. John at Philadelphia did not diverge from this tendency. It is therefore quite possible that the two side elevations (north and south) reflected in their articulation the presence of the barrel vaults behind them. According to our reconstruction, illustrated in figure 139, the north and south tympana403 were probably crowned by segmental brick arches. These arches followed the curvature of the barrel vaults behind them, and sprang directly from the extrados of the blind arches.404 As in St. Eirene, and similarly to other examples from Early and Middle Byzantine ecclesiastical architecture, the crowns of the wide arches extended over the level of the upper horizontal cornice. The eave line was curved over these arches, and marked by a dogtooth frieze, similar to the one found over the east arch of the church.

The vault facing depicted in figure 139 constituted a largely autonomous building skin. This skin, with most of its elements being very thin and inadequately bonded to the robust structure of the church’s interior, must have been one of the first victims of the dilapidation of the fabric. The arches crowning the tympana, and masking the barrel vaults have not left a single trace in the surviving structure. Some blind arches, recesses, and parts of dogtooth friezes are the only surviving features attesting to what was a sophisticated and rich composition. A brief comparison between the reconstructed elevation of figure 139 and the bare, plain elevations of buildings such as Hagia Sophia and St. Eirene at Constantinople convinces us that our elevation is not typical of standard early Byzantine building. The lack of any pattern, or sculptural effect in the facing of Building D at Sardis, a building that otherwise seems to have emerged from the same building tradition as St. John, also serves to illustrate the atypical nature of St. John’s elevations. Reconstructing this elevation, I have been tempted to follow M. F. Castelfranchi in attributing this elaborate articulation to Middle Byzantine alterations carried out in the elevations of the monument, several centuries after its building.406 Still, this hypothesis does not seem to be corroborated by our survey of the structural fabric of the church: the bricks of the external blind arcade and the mortar beds between them seem to have a similar size to the ones used in the main vaults.407 In addition to this, there is no continuous joint or other indication that the vaults and their facing belong to different building phases.408 Therefore, at least for the time being, we should consider the main lines and structures of the elevation that has just been reconstructed as contemporary to the vaults of the church.

On both the north and south elevations, the arcade was flanked by brick pilasters decorated with niches, and projected 30cm beyond the face of the side arches. These pilasters served a double purpose, and responded to both aesthetic and practical considerations. Firstly, they “framed” the varied elements of each elevation and strengthened the corners visually. Secondly they constituted transitional elements at the corner between elevations whose articulation differed. Indeed, according to the remains, the east and south elevations of the church had a slightly different articulation. In the north elevation, the recesses of the blind arches must have been limited to the upper tier of the facing; in the east elevation however, these recesses were part of continuous niches occupying the entire height of the facing.405 This discrepancy is internal barrel vaults “does not exactly correspond with the large arches in the north and south walls of the building”. This means that the arches in the elevation are not formed by the edges of the internal barrel vaults, but constitute independent structures. 403 Tympanon: The thin wall closing the barrel vaults externally. It is either located behind the barrel vaults, or, alternatively, next to their external face. 404 Similar blind arcades, where wide arches with windows below them alternate with narrower blind arches, are found mainly in Middle Byzantine churches in Constantinople and Thessaloniki. Two characteristic examples are the south elevation of the church of Christ of the Chora at Constantinople, as well as St. Mary of the Coppersmiths at Thessaloniki (see C. Mango, 1978, p. 114, pl. XV). The reconstruction drawing of the north elevation of Lascarid Church E at Sardis by Hans Buchwald, published in C. H. Greenewalt et al. (2003, p. 118), also features such a blind arcade. This elevation feature occurs in the 14th century church of the Virgin Hodegetria, or Afentico at Mistras, which is described in G. Millet (1910, p. 25), as well as in many other examples. 405 The face of the north blind arches must have been almost flush with the face of the wall that originally enveloped the pier, and is now missing. Therefore, in the north elevation, only the upper zone was articulated with niches. The lower zone, probably separated from the upper one with a cornice, had a plain face, as indicated by the excavated remains. On the other hand, the face of the east blind arch must have protruded beyond the face of the east outer wall. In this case, the pilasters supporting this arch did not stop at a horizontal cornice but continued all the way down, through the lower zone of the elevation. The lack of stylistic unity between the elevations of the building characterizes a great number of Middle Byzantine churches in Greece, such as Hosios Loukas, at Phokis and St. Mary of the Coppersmiths at Thessaloniki.

The Central Vaults The three pendentives found in the remains of St. John make it certain that both the two surviving bays of the church were covered by a certain kind of dome on pendentives. Due to the absence of any remains of these domes, we cannot easily determine their detailed form. However, an interpretation of the limited archaeological remains can yield indirect evidence for the geometric profile and, in particular, the steepness of these domes. Comparisons with similar early Byzantine vaulted 406

This hypothesis, published in M. F. Castelfranchi (1999, p. 97) is based on the existence of dogtooth friezes, blind arcades, recesses, all of them elements typical of Middle Byzantine façade ornamentation. 407 Large square bricks measuring 70x70x4.5cm and smaller rectangular ones measuring 35x70x4.5cm seem to have been used throughout the structure. The thickness of the mortar beds, around 4cm, is subject to small variations but these occur both in the facing and in the vaults. 408 H. Buchwald (1981, p. 304), has come to the same conclusion.

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140. Philadelphia, St. John, reconstructed, cut-away axonometric. According to this reconstruction, the nave is covered by two hemispherical domes on pendentives (drawing by Karolina Vasilikou and Nikolaos Karydis, 2009).

basilicas whose vaults survive, or can be plausibly reconstructed, may also prove to be helpful. The consideration of this evidence, bearing in mind also the liturgical planning of the early Byzantine church, makes the hypothetical reconstruction of the vaults of the monument possible.

major axis, while broad supporting arches expanded each square, domed bay into a cross shape (fig. 140). Another approach to the reconstruction of the vaults could be based on comparisons with other churches. The large variety of dome types employed in Early Byzantine churches can make it difficult to draw conclusions from such comparisons.410 Yet, since it is only the geometric profile of the vaults that interests us here, we just have to deal with two broad categories: hemispherical and shallow domes on pendentives. By focusing on vault

In our survey of St. John at Ephesos, we found that a detailed examination of pendentive fragments can form the basis for the reconstruction of the upper portion of the vaults.409 The same method may be applied at Philadelphia, where the pendentives are better preserved than in Ephesos. The pendentives at Philadelphia sprang from the extrados of the arches rather than from their faces. In chapter 3, we showed that this construction detail is typical of pendentives carrying hemispherical domes. This suggests that the church was covered by two hemispherical domes on pendentives disposed along its 409

410

There are ribbed and pumpkin domes; there are shallow and hemispherical ones, with or without windows. The three surviving 6th century churches of Constantinople offer a good example of this variety. The four domes found in their naves are all different. The nave of St. Eirene is covered by a simple hemispherical dome on pendentives and a pendentive dome; the central bay of Hagia Sophia is roofed with a ribbed hemispherical dome, whereas the shape of the dome of the church of Sts. Sergios and Bakchos approximates to the one of a pumpkin dome.

See above, Chapter 3, section III, 1.

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The Vaults of St. John the Theologian at Philadelphia (Alaúehir) entirely absent from St. John in case its bays were covered by identical vaults. An adoption of such a vaulting solution would signify a departure from liturgical planning standards observed in many early Byzantine vaulted churches. Indeed, the tendency to use the dome as the center of the architectural composition is encountered in the quasi-totality of early Byzantine churches. The late 5th century domed basilica of Meriamlik, the 6th century churches of Qasr Ibn Wardan and Basilica B at Philippi, and possibly St. Titos at Gortyna (Crete), have long served to illustrate the beginnings of a building typology where the basilican plan is organized around a domed bay.

layouts of early Byzantine churches that are typologically similar to St. John, the number of the possible vaulting solutions is narrowed.411 An obvious comparison would be the one with Building D, at Sardis, a monument reconstructed with two pendentive domes surmounting its major bays.412 As both buildings seem to belong to the same building tradition, their vaults are likely to have been similar. This seems to justify the hypothetical reconstruction of St. John with shallow as opposed to hemispherical vaults, as illustrated in figure 141. The two tentative graphic reconstructions attempted so far are characterised by plural identical domes.413 A criticism against the reconstruction of such a vaulting pattern could be based on its lack of climax, and the absence in it of a clear hierarchy between the vaulted bays. One could argue that in most early Byzantine vaulted basilican churches the hemispherical dome tends to be used as a means to attribute emphasis to a specific part of the church. Often, the dome seems to be a culmination point rather than a module.414 It tends to be used to give emphasis to the transition from the nave (ȞĮȩȢ), to the sanctuary (Țİȡȩ).415 According to a similar interpretation, the hemispherical dome was a symbolic element destined to mark the space occupied by the elements constituting the focal points of the liturgy: either the ambo or the altar.416 This emphasis would have been

From a liturgical point of view, the vaulting layout of buildings such as Basilica B, at Philippi and St. Eirene at Constantinople, may be considered as a better point of departure for the reconstruction of the vaults of St. John.417 The naves of these two monuments, not unlike the one of St. John at Philadelphia, are divided in two bays. Their vaulting, on the other hand, is characterised by the early Byzantine use of the hemispherical vault on pendentives as the culminating point and climax of the architectural composition.418 Indeed, in both cases, the use of the hemispherical dome is reserved to the eastern bay, where the nave meets the church’s sanctuary. The possibility that St. John at Philadelphia had a vaulting layout that resembled “centralised basilican churches”,419 such as St. Eirene and Basilica B, is explored in the graphic reconstruction of the monument depicted in figure 142. According to this hypothesis, a hemispherical dome on pendentives gave the east bay a predominant character, and a pendentive dome surmounted the west bay.

411 The similarities of the church of St. John with early Byzantine churches such as St. Eirene and the Holy Apostles in Constantinople, Basilica B in Philippi, St. John in Ephesos, and Building D in Sardis have already been noted by H. Buchwald (1981, pp. 316–317 and 1984) who also refers to a series of churches with three and five domes found in Cyprus. To these examples we should add Building IV (possibly a Martyrium) within the Episcopal complex of Side (see A. M. Mansel, 1978, pp. 264, 269). Indeed, not only does the plan of this building resemble the one of St. John, but its vaults, two domes on pendentives, partly survive. We should note however that the scale of the building is much smaller than the one of St. John, and its materials very different. All these buildings are characterised by the division of their nave to rectangular or square bays covered by either domes on pendentives or pendentive domes. 412 A similar vaulting pattern is found in the mausoleum of Abradas, within the sanctuary of the Seven Sleepers at Ephesos. This is also an aisleless twin-bayed building. This building has been unconvincingly reconstructed with two ellipsoidal domes in FORSCHUNGEN IN EPHESOS IV/2, pp. 82 – 87. Such domes do not seem to adapt well to the rectangular shape of bays. A reconstruction with two pendentive domes, as in Building D at Sardis is more probable. 413 Repetitive vault patterns occur in St. John the Theologian at Ephesos and in the church of the Holy Apostles at Constantinople. St. Mark in Venice and the small Middle Byzantine church at Peristerai, near Thessaloniki indicate that such vaulting layouts have been emulated in later periods. For a comparative study of the above churches, and the interpretation of their role in the development of Byzantine architecture, see H. Buchwald (1984, p. 209). 414 For the role of the dome as a central element in early Byzantine vaulted churches, see R. Krautheimer (1986, p. 203). 415 For a discussion concerning the spatial divisions of the early Byzantine church, and the role of the area in front of the sanctuary in early Byzantine liturgy, see Th. Mathews (1971, pp. 117, 172). 416 According to A. Grabar (1946, pp. 395, 398), both in St. Sophia at Constantinople, and in St. Nicholas at Myra, the ambo was located immediately below the hemispherical vault that crowned the edifice. The same author claims that in early domed basilicas, such as Cariþin Grad and Ilissos Basilica at Athens, the dome served as reminiscence of the Martyrium building typology. This interpretation seems to exclude

the possibility of a repetitive use of a dome within an early Byzantine basilica. The use of the dome as a modular unit would break any symbolic connection with Martyria, in which the dome is the unique center of the composition. Also, such a repetitive use seems to be incompatible with the symbolic weight of an architectural element meant to represent the celestial sphere or, as J. B. Ward-Perkins (1994, p. 310) put it, “the canopy of heaven, the symbolic covering proper to the person of a divinity or of his representative on earth, the divine monarch”. 417 According to H. Buchwald (1981, p. 317) St. Eirene at Constantinople and Basilica B at Philippi are comparable to St. John at Philadelphia. R. Krautheimer (1986, p. 489), has refuted the pertinence of this connection. Yet, he based his argument on two hypotheses that are not proved. Firstly, he claims that in both [Justinian’s] St. Eirene and Basilica B, “a barrel-vaulted nave preceded the single domed bay”. This statement contradicts a description of Basilica B by the same author (p. 253). It also overlooks the possibility, mentioned by H. Buchwald (1984, p. 213) that the shallow dome over the nave of St. Eirene may date back to the 6th century. Secondly, R. Krautheimer takes it for granted that the nave of St. John at Philadelphia was covered by two identical domes. 418 The nature of the original, 6th century vaults of St. Eirene cannot be determined with certainty, as we are not certain about the extents of the 8th century reconstruction carried out in this church. Despite this, U. Peschlow (1977), W. S. George (1913, pp. 42–46), H. Buchwald (1984, p. 213), and T. Mathews (1971, p. 82, fig. 42) believe that the first vaulted phase of St. Eirene included only one hemispherical dome on pendentives. 419 This term, which seems to us to be more precise in this context than the designation “domed basilica”, has been used by R. Mainstone (1988, p. 285).

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141. Philadelphia, St. John, cut-away axonometric. Reconstruction with two domical vaults (drawing by Nikolaos Karydis, 2009).

142. Philadelphia, St. John, cut-away axonometric. Alternative reconstruction showing composite vaulting scheme (drawing by Nikolaos Karydis, 2009).

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The Vaults of St. John the Theologian at Philadelphia (Alaúehir) There are two doubts concerning this third reconstruction. First, it does not seem to correspond fully with the archaeological evidence. As the pendentives of the two bays had an identical structure, it is unlikely that they developed into vaults so different. Also, the existence of two different vaults over the nave seems to be in conflict with the subdivision of its plan in two identical square bays. We are thus confronted with two plausible reconstructions of St. John at Philadelphia. The reconstruction with two pendentive domes is based on the comparison with Building D at Sardis, found in the immediate vicinity of St. John. Still, this reconstruction overlooks an important difference between the plans of the two buildings: the bays of St. John are square, whereas the ones of Building D have an oblong shape. It is questionable whether the similarity between the pier profiles of the two buildings is enough to indicate that their vaulting patterns were identical. On the other hand, the reconstruction with two hemispherical domes on pendentives is the only one to be based on archaeological evidence, namely the connection between pendentive and arch fragments.420 The small Martyrium at Side shows that such twin-domed vaulting patterns were not unknown in west Asia Minor. We therefore consider this reconstruction to be the most probable, in spite the difficulties in its justification from a liturgical point of view.

420 As shown in Chapter 3, III, 1, the pendentives of St. John at Ephesos rest on the extrados of the supporting arches, just like the pendentives that carried the hemispherical domes of St. Eirene and Hagia Sophia at Constantinople.

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143. Ephesos, St. Mary, view of the remains from the narthex looking east. This view combines elements from different building phases. The ashlar masonry apse in the background was the termination of a columnar basilica. The brick masonry piers in the foreground belong to a domed church that replaced the west part of the basilica.

144. Ephesos, St. Mary, Overall view of the remains from the chamber south of the great apse looking northwest. In the foreground, we can distinguish the remains of a pillared basilica. The remains of the massive brick and rubble piers of the domed church dominate the background.

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Chapter 6 The Vaults of St. Mary at Ephesos

1. Introduction The clarity with which the succession of building phases is reflected in the architectural form of St. Mary makes the latter unique among the churches of west Asia Minor (figs. 143, 144).421 The fact that the phases are recognisable gives a special dimension to our survey of vault remains in this church. The surviving fragments offer information about the nature of the development of vaulting techniques employed at Ephesos throughout the early Byzantine period. However, the evidence from the vault fragments of St. Mary, mostly deriving from secondary vaults (fig. 145), is not enough to constitute the basis of a graphic reconstruction of the entire original vaulting pattern of the church.

145. Early, columnar basilica, north side chamber, southwest corner. Notice the remains of the pendentive dome that covered the chamber (right), as well as the shallow barrel vault of the staircase between chamber and apse (left).

The first attempt to reconstruct the vaults of St. Mary and its baptistery was made in the context of the first excavation report on the monument.422 These reconstructions are often too diagrammatic, showing the brick layout of vaults only in plan. Also, at least two of them do not entirely correspond with the vault fragments on which they were based.423 Almost two decades later, F. Fasolo published a comprehensive analysis of the structure of the church and the baptistery, but did not give enough attention to the secondary vault fragments.424 Still, Fasolo has proposed a convincing reconstruction of the domed phase of the church.425 Since the 1960s, in spite of the systematic appearance of publications on the dating of the several phases of St. Mary, there were no further attempts to investigate the vaults of the church.426

Thus, the opportunity to record fragments that had escaped the attention of F. Knoll and F. Fasolo was missed. The primary purpose of my following investigation is to analyse the vault remains of all the early Byzantine phases of St. Mary, and, where possible, to use these remains as a basis for the reconstruction of the vaults. Vault types from each phase can then be compared in the hope to distinguish the techniques that underlie the development of vault construction employed here from the mid-5th century, to the late 6th century. Due to the loss of the main vaults, reconstruction has to rely on comparisons with other, better preserved churches of a similar stylistic current in west Asia Minor and Constantinople.

421 Indeed, St. Mary has a composite character, made up from the merging of different architectural typologies. As S. Karwiese (1999, p. 84, fn. 22) has demonstrated, in a certain stage, the main body of St. Mary consisted of a cross domed basilica in the west and a timber roof basilica in the east. Earlier publications, mentioned by Karwiese with bibliographical references, had considered the two parts to belong to different building phases. 422 For very brief references to the vault remains and their proposed reconstruction – often inaccurate, see F. Knoll (1932, pp. 33–34, 55) 423 See F. Knoll (1932, figs. 37, 64) for a tentative reconstruction of the vault over the north side chapel the east basilica, and an accurate but largely diagrammatic representation of the vaults of the north side chamber of the cross domed church. 424 In F. Fasolo (1956, p. 6) there is hardly a reference to the roof of the ambulatory of the baptistery. Idem, (p. 3, fig. 3) refers very briefly to the vault fragments found north of the early apse of the church, without describing them in detail, or reconstructing them. 425 See F. Fasolo, (1953, pp. 76–79 and 1956, pp. 1–22). 426 Cf. P. Verzone (1965, pp. 610–613), C. Foss (1979, p. 52), and A. M. Castelfranchi (1999, p. 89).

2. An Overview of the Vault Fragments of Saint Mary and their Dates In spite of several excavations in the remains of St. Mary, and although this church is one of the largest in west Asia Minor, few fragments of its vaults survive. Most of these belong to small, secondary vaults covering staircases,

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146. View of the baptistery of St. Mary looking northwest. Notice the imposing remains of the vault fragment on top of one of the piers of the inner nucleus of the building.

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The Vaults of St. Mary at Ephesos chapels, and ancillary spaces.427 The earliest vault remains of the church proper are probably the ones found in the side chambers flanking the apse of the 5th century basilica, as well as the vaults of the two staircases between chambers and apse (fig. 145).428 The materials and structural layout of these vaults seem to indicate that they belong to the same building phase. Given the structural continuity between vaults and apse, both must be dated to the 5th century AD.429 It has been suggested that this same building phase included the building of the baptistery north of the atrium.430 The latter’s remains include a series of small vault fragments whose potential to offer information about the original form of the building has not been sufficiently appreciated by F. Knoll (fig. 146). All these early fragments illuminate the early emergence of vaulting in the 5th century and, possibly, its marginal role at a period when timber roof basilicas dominated ecclesiastical architecture.431 The following building phase of St. Mary – with a 6th century date – involved the erection of a church entirely covered by vaults. Unfortunately, of these vaults only the secondary – but relatively well preserved – vault fragments survive. They are found in their original context, over the long chambers within the massive east piers of the church (fig. 147). The surviving fabric constitutes an excellent field for observation of fragments belonging to small-scale vaults. These remains reveal a particular aspect of Early Byzantine vault construction, which could not be fully appreciated in previous monuments, where our survey was focused on major vaults.

147. Ephesos, St. Mary, cross-domed church, south side chamber (inside the pier) looking west. The pitched brick barrel vault covering the room is one of the few surviving early Byzantine vaults.

427 Few fragments are also found scattered in the remains of the baptistery. Among them, there is a fragment of a major vault, possibly a dome. This is probably the only surviving fragment of a major vault in the entire complex. 428 As we have seen, there have been many theories about the dating of the first phase of the church. For an early 5th century dating, which is well substantiated, see F. Fasolo (1955, p. 13). For a late 5th century dating (much after the Ecumenical Council of 431 AD) see S. Karwiese, (1999, p. 83). For a synopsis of all the dating theories, proposing dates ranging from the early 4th to the early 6th centuries, see R. Krautheimer (1986, p. 471, fn. 13), and H. Buchwald (1999, p. 12, fn. 23). 429 According to F. Knoll, the nave and aisles of the 5th century “basilica with the columns” (Säulenkirche) had been covered by a timber roof. We should examine the possibility that the vault fragments in the side chambers of the basilica belong to a remodeling that at some point replaced an original timber structure. Evidence for this has been identified by F. Knoll (1932, p. 33). The latter has claimed that the corner pilasters supporting the vaults were autonomous elements added to the corners of the chapel. That seems to suggest that the vaults over this chamber were added, together with the corner pilasters during a subsequent rearrangement of the roof of the east part of the Basilica. However, the vaults covering the two staircases are unlikely to belong to a different phase from the one of the 5th century apse. 430 F. Fasolo (1955, p. 5, fn. 4) has based his suggestion that the baptistery and the early basilica are contemporary structures on the fact that in both their remains we witness the use of a characteristic kind of gray mortar (which probably contains volcanic sand). 431 Indeed, according to C. Mango (1978, p. 58) “[timber-roof] basilicas [as opposed to vaulted churches] constituted the vast majority of churches that were put up in the 6th century”.

148. Ephesos, St. Mary, columnar basilica, south side chamber, detail of corner buttress with recessed profile.

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149. Ephesos, St. Mary, columnar basilica, north side chamber. Fragment of pendentive dome (see also fig. 145).

one that F. Knoll described.432 Whereas in a normal pendentive, the edges of the conical brick courses constitute arcs laid horizontally, in this occasion, the edges of the flat brick courses (E) constitute arcs that have a gradually increasing inclination, as if they were marking the steps of a gradual rotation around the notional cross axis of the base of the vault (A). This observation is crucial for the accurate reconstruction of the vault. Its courses must have formed a spherical surface, in the same way as the rotation of a circular arc generates a sphere (fig. 150). The topmost brick course of this vault must have risen higher than the apices of the supporting arches. We can thus visualize this structure as a pendentive dome, an ideal vaulting solution for an oblong chamber, whose plan was not easily adaptable to a hemispherical dome on pendentives (fig. 151).433

3. The Vault Fragments of the 1st Building Phase The Vaults of the Side Chambers of the Early Church The most intriguing of St. Mary’s minor vault fragments is the one found in the north side chamber of the early basilica. The existence of pilasters with re-entrant angle profiles in the four corners seems to indicate that arches surrounded this chamber (fig. 148). Indeed, the remains of an arch built with bricks laid radially can be recognized against the south wall. This arch supports a very peculiar vault fragment, which cantilevers outwards as if it was suspended from above (fig. 149). The extrados of the arch forms the point of departure of brick courses, which form arcs with a gradually increasing inclination from the horizontal. The edges of these brick courses form a continuous face against the extrados of the arch.

Although there is nothing unusual about the original geometrical form of this vault, the way in which it was constructed seems to deviate from standard building

The external surface of this vault fragment has a double curvature. This suggests that it had originally been part of a typical pendentive. Yet, figure 148 shows that we are, in fact, dealing with an atypical structure, quite unlike the

432

See F. Knoll (1932, pp. 33–34). F. Fasolo (1956, p. 3) also suggested that this fragment must have been part of a pendentive dome. However, in his brief reference to it, he does not discuss the brick layout nor does he offer any proof for his reconstruction.

433

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The Vaults of St. Mary at Ephesos

150. Ephesos, St. Mary, columnar basilica, north side chamber. Interpretive axonometric diagram of spherical vault with radiating arched courses (drawing by Nikolaos Karydis, 2009). practices. The first step of its construction must have been the erection of the four semi-circular bounding arches, themselves supported on corner pilasters.434 I have designated the manner of construction that followed: spherical vault construction with radiating arched courses. According to this method, the courses of the vault were not laid on conical beds, according to the usual practices, but on radiating, arched beds whose inclination from the horizontal increases as we move from the base to the apex (fig. 152). Thus, the lowest courses are almost horizontal, while the topmost course must have consisted of bricks laid vertically.

constructed spherical vault is not completely “locked in position” until all their bricks are in place.435 To build such a vault, one needs some form of temporary support. Another problem is that the shape of the template used has to be adjusted as the builder moves from one course to the other. In our particular vault, on the other hand, the masonry is divided into a series of radiating courses whose small length and arched shape allow them to be kept in place during construction with limited temporary support. Moreover, as the courses are identical, the same template can be used throughout the construction process.

The choice of such a peculiar structure must be related with the need to economise on centering. Each of the circumferential, conical brick courses of a traditionally

Staircase Vaults The vaults covering the two staircases that flanked the 5th century apse, although slightly different in form, also seem to follow an unconventional construction practice,

434 As in Building D at Sardis, and the west nave of St. John at Ephesos, not to forget the corner chambers of Hagia Sophia’s galleries, the height difference between the apices of the bounding arches does not seem to have deterred the builders from constructing a pendentive dome on them. The crown of the arches that spanned the narrow sides of the room must have been by at least 80cm lower than the crowns of the arches that spanned the long sides.

435

For an overview of the standard dome construction practices, see C. Mango (1978, p. 11), A. Choisy (1883, pp. 37–41, 61–62), and R. Mainstone (1988, p. 212).

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151. St. Mary, columnar basilica, reconstructed, cut-away axonometric of the north side chamber showing peculiar pendentive dome structure. Surviving remains are shown with a black outline (drawing by N. Karydis, 2009).

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The Vaults of St. Mary at Ephesos

152. St. Mary, columnar basilica, reconstructed sections of the north side chamber showing pendentive dome built with arched brick courses (drawing by Nikolaos Karydis, 2009). revealing a striking virtuosity in the use of brick.436 In both staircases we are dealing with barrel, or pseudobarrel vaults, with a far shallower pitch than that of standard early Byzantine barrel vaults (fig. 153). 437 The manner of construction followed in both staircases involves the use of brick courses laid on their edge. These are not normal to the intrados of the vault, but lean considerably. They are laid diagonally, in a herringbone pattern, and interlock along the longitudinal axis on the top of the vault. But that is where differences between the two staircases begin. The vaults over the south staircase have a curved internal surface and consist of brick courses set on convex beds (fig. 154). In the north staircase, however, the intrados of the vault is composed of two almost flat surfaces, giving the vault a triangular profile (figs. 154, 155). Each of the vault planes consists of diagonal brick courses, this time set on roughly flat (if not concave) beds. Both structures, in spite of their differences seem to constitute variations of a structural type I have designated shallow barrel vaults with a herringbone brick pattern.438 436 F. Fasolo (1956, p. 6) also considers this brick layout as characteristic of highly competent building. 437 The axis of these vaults follows the inclination of the flights of stairs. 438 The remains of the north staircase include a fragment of the shallow, spherical vault that covered the third landing one met ascending the staircase. This vault sprang from a surrounding border formed with two pitched brick courses. Its shell consisted of courses laid diagonally across the corners and interlocking along the two cross-axes.

153. St. Mary, columnar church, south side chamber. Detail of the shallow barrel vault covering the south staircase, looking north. 141

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154. St. Mary, columnar basilica, reconstructed axonometric drawings of the staircase vaults. Note the structural differences between the vault of the south staircase (left) and the vault of the north one (drawings by N. Karydis, 2009).

The barrel vaults of the staircases give us a rare insight into the role of improvisation in early Byzantine construction. Each of the vaults could perhaps be attributed to different group of builders and interpreted as an improvisation on a common vaulting type. The fact that such variations were tolerated shows that individual groups of builders enjoyed a certain independence from the co-ordinator(s) of the construction procedure, and had the latitude to adapt the desired scheme to their own particular métier. The Vaults of the Baptistery Introducing us to his reconstruction of the baptistery of St. Mary, Fritz Knoll (1932, p. 47) makes the following comment: “there are so many finds and points of reference that the representation [of the original form of the baptistery] can be carried out without any lacunae”. This statement predisposes us to expect a reconstruction of the vaults of the building based on an exhaustive analysis, and correct identification of their surviving fragments. Unfortunately, this reconstruction does not entirely fulfil this promise: references to vault remains as indications of the nature of the original vaults are not accompanied by a scrutiny of the fragments. The author

155. St. Mary, columnar basilica, north staircase. Detail of shallow barrel vault (cf. fig. 154). 142

The Vaults of St. Mary at Ephesos

156. Baptistery of St. Mary, view of vault fragment A from the north. Note the remains of a pitched brick barrel vault shell on the top right corner of the figure.

157. Baptistery of St. Mary, view of vault fragment A from the southeast. Notice the wedge-shaped plan.

misidentifies at least two of the fragments of the baptistery. The reconstruction of the roof over the ambulatory relies less on archaeological evidence, than on preconception.439 The resulting reconstruction does not correspond with evidence from vault fragments (see fig. 146). In spite of these shortcomings, Knoll’s publication constitutes a useful basis for further research into the monument since it contains a photographic record of vault fragments that no longer exist.

There are eight piers numbered from 1 to 8, starting from the pier left of the south entrance and continuing in a clockwise direction (see fig. 6). Fragment A sticks out and is usually the first one to attract the visitor’s attention (fig. 156). It is a broad, thin slice of masonry, which now lies on its edge on top of the remains of Pier 3. This fragment is valuable for displaying the entire wedge-shaped profile of the upper portion of the piers as well as the inner layers of their brick structure (fig. 157). In the present context, we are particularly interested in the vault remains found in the present west facing of the fragment. This vault fragment has a cylindrical surface and is composed of pitched brick courses. These characteristics indicate that these remains belonged to a barrel vault. Indeed, given the fact that these remains lie against the broader side of the pier’s profile, the vault to which they originally belonged must have been located over one of the narrow passages of the west ambulatory.440

My survey of the baptistery identified four masonry fragments belonging to parts of the structure that have been destroyed. Describing the location of these fragments, we will use the piers as points of reference. 439 F. Knoll (1932, p. 49) suggests a timber roof for the ambulatory for two reasons: because the surrounding walls are too thin to support the weight of vaults; and because the plan of this ambulatory is too irregular to be covered by vaults. The first reason should not have been used: the proportional relationship between wall thickness and roof span in the ambulatory is 1:2. In the vaulted aisles of St. John at Ephesos the same ratio is 1:4 (A. Thiel, 2005, pp. 26, 31, 111). Also, it is not true that the irregular plan of the ambulatory is not compatible with a vault layout. R. Krautheimer (1986, figs. 164, 180) and R. Mainstone (1988, p. 81), show that in Hagia Sophia, and Sts. Sergios and Bakchos at Constantinople, not to forget St. Vitale in Ravenna, the irregularity of aisles and galleries does not hinder their covering by vaults. In Hagia Sophia in particular, the form of some of the vaults is complex and not geometrically regular, because of the need to adapt to the curves, in plan of the exedrae colonnades. Therefore, to claim that such an irregularly shaped space could not be covered by vaults is to underestimate the flexibility of early Byzantine vaulting techniques.

Fragment B, presently lying upside down on top of the remains of Pier 7, includes in its southwest side elements

440

An early photograph of the fragment occurs in F. Knoll (1932, fig. 48). The latter, identified these same remains as parts of a semi-domes covering one of the semi-circular niches facing the ambulatory. This interpretation of the remains fails to take into account their geometry, which is by no means spherical.

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158. Baptistery of St. Mary, detail of vault fragment B, showing remains of a barrel vault.

159. Baptistery of St. Mary, view of vault fragment D, probably part of a groin vault.

of a cylindrical vault with a mixed structure (fig. 158).441 Its upper part (originally the lower part) consists of horizontal brick courses corbelled out, whereas the lower part (originally the upper part) seems to be made partly of horizontal and partly of pitched brick courses. Pitched and horizontal courses meet along diagonal curves. Both the shape and structure of this fragment lead us to interpret it as part of a barrel vault. The considerable length of this vault fragment, around 3.10m, as well as its present location attest that its original location was over one of the narrow passages of the east ambulatory, each about 3.20m long.

The visualisation of the ambulatory with groin vaults seems to be confirmed by fragment D, now situated on top of the wall separating the baptistery from the Atrium of the church (fig. 159). The layout of the bricks here is strongly reminiscent of the structure of fragment C: five arched courses laid on conical beds seem to spring from a circular, sloping bed on top of a masonry wall.443 The existence of such groin vault fragments both in the south and the north corridors of the ambulatory attests that this vault type was systematically used over the secondary spaces of the baptistery. The fragments described above reveal that a great part of the ambulatory was vaulted. Barrel vaults built partly with over-sailing horizontal courses and partly with pitched bricks covered its narrowest parts. In the areas where the ambulatory became wider, its space was probably articulated into bays, which were separated by transverse arches.444 These bays seem to have been covered by groin vaults built with pitched bricks. These secondary vaults were made of bricks measuring approximately 35x35x5cm set in neat, common bond. The shells of these secondary vaults were all one normal brick in thickness. Over these shells there were solid fills of mortared rubble. The thickness of this fill seems to suggest that the vaults over the ambulatory were covered, so as to be invisible from the building’s exterior.

Fragment C, standing loosely on top of a steel rod between piers 5 and 6, in its poor state of preservation, can hardly be used as source of information about the nature of the original vaults. This fragment can only be studied with the help of a photograph published by F. Knoll, (1932, p. 43, fig. 41). According to this photograph, in the 1930s, this fragment conserved the four brick courses laid on edge upon a sloping bed. The fact that the length of the courses diminishes from bottom to top signifies that this fragment was in fact the quarter of a groin vault, built according to standard early Byzantine methods, employing bricks laid on edge.442 The original location of the vault to which this fragment belongs cannot be accurately established. However, the fragment’s location next to pier 5 seems to suggest that it formed part of the vaulted roof of the north ambulatory. In this area, a sequence of pilasters projecting from the north wall of the building divides the centre of the north corridor in three irregularly shaped bays. Fragment C suggests that these three bays were covered by groin vaults.

Unfortunately, the baptistery of St. Mary no longer conserves traces of the central vault over the large baptismal basin. Yet, back in 1932, extensive arch and pier fragments (including fragment A, which has already been examined), had allowed Knoll to reconstruct the form of the baptistery’s central rotunda. Most of these fragments no longer survive. The photographs published in the 1932 excavation report constitute the only record of these remains, and the only basis for our attempt to reconstruct the vaults of the rotunda.445

441

See F. Knoll (1932, fig. 42). Similar vaults occur in a wide range of early Byzantine buildings. Those at the narthex of St. Eirene have been discussed in W.S. George (1913, pp. 36–37), and those of Hagia Sophia have been photographed, but, unfortunately, inadequately described, by R. Mainstone (1988, fig. 98). C. Mango (1978, fig. 112, 114), has published two photographs of the remains of the church of Qasr Ibn Wardan, in Syria, which show a number of such vaults in a fragmented state. These vault fragments are quite similar to the one appearing in F. Knoll’s photograph. 442

443

This same fragment also includes remains of another vault: in the side of the fragment that now faces north, we can distinguish an extensive part of a barrel vault with bricks laid radially. 444 The existence of such arches is echoed by two pilasters projecting from the external face of the two north piers into the ambulatory. These pilasters are described in F. Knoll (1932, p. 45). 445 See F. Knoll (1932, fig. 48, 49, 53).

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160. Baptistery of St. Mary, hypothetical reconstruction of the dome on the basis of fragments recorded by F. Knoll, 1932 (drawing by Nikolaos Karydis, 2009).

between the arches was not built in the conventional way, with horizontal brick courses, but with arched courses interlocking along a notional vertical axis between the arches. A possible interpretation of such a structure could be that these spandrels were meant to ensure a transition from a roughly octagonal plan formed by the eight arches to the circular springing course of the dome. Such a transition would require the spandrels to be shaped as spherical triangles, justifying the setting of bricks in arched courses, a technique mostly applied in vaults, instead of laying the bricks in horizontal courses, a technique mainly used in masonry walls.

Knoll’s photographs indicate that the drum of the rotunda consisted of eight piers connected by broad arches. These arches had a conical shape that made their external face considerably wider than the inner one.446 They seem to have sprung from relatively thin marble blocks (merely 15cm high). The main body of each arch consisted of two rings, made with common-size bricks laid on radiating beds. The only peculiarity of the structure of the drum is found in the spandrels, the curious structure of which seems to have eluded the attention of the Austrian excavators. As one of the fragments indicates, the wall 446 The photographs published by F. Knoll, do not offer enough information about the structure of the soffit of the arches, and therefore, it is difficult to say in which way the widening of the arch towards its exterior was achieved. Even less is known about the nature of the face of the arches. It is not clear whether the latter followed the cylindrical shape of the drum, or if it was flat. Given that the fragments photographed are now lost, it seems that these questions will never be answered.

Among the fragments photographed in the 1930s, there is one that probably comes from the base of a large cupola. This fragment seems to demonstrate the use of atypical dome construction methods, which remind us the techniques studied in the nave of St. John at Ephesos. It consists of a bottom part made of horizontal courses of

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161. Baptistery of St. Mary, reconstructed axonometric. Note the scale-like brick pattern of the major dome, and the various pitched brick vaults of the ambulatory. Grey outlines demarcate the surviving fragments on which this reconstruction was based (drawing by Nikolaos Karydis, 2009). bricks with their tops arranged in a series of three semicircular arches, and an upper part made of arched brick courses, which interlocked along the meridians of the dome.

The reconstruction shown in figure 160, although based on a fragment clearly suggestive of such a herringbone brick pattern, seems to be slightly problematic from a structural point of view. The existence of meridional joints and the ensuing lack of overlapping between bricks and vertical mortar joints along these meridians would reduce the capacity of the dome’s masonry to counteract hoop tension. This would make such a dome structure considerably more susceptible to meridional cracking than a conventional structure.447 Such a dome could easily turn to a ring of independent partial arches, all leaning against the crown. Although such cracking is not necessarily critical,448 it results in increased outward

This fragment suggests two possible reconstructions of the structure of the dome. According to the first scenario, construction in the rest of the cupola continued as indicated by the fragment of its base. According to this hypothesis, illustrated in figure 160, the main mass of the dome consisted of a series of meridional strips growing thinner towards the top. Each of these strips was made of arched brick courses (C in Figure 160) set on conical beds with a gradually increasing inclination from the horizontal. Although such a structural fabric would have created a pattern reminiscent of an umbrella, its surface would have been perfectly spherical.

447

For the formation of meridional cracks in dome structures see J. Heyman (1995, pp. 35–36), as well as R. Mainstone (1988, p. 165). 448 Indeed, this was the conclusion of the report Poleni made on the dome of St. Peter as early as 1748. See J. Heyman (1995, p. 39).

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The Vaults of St. Mary at Ephesos thrusts from the dome’s constituent arches on the supports.449 I consider unlikely that the builders of the dome of St. Mary’s baptistery, whose constructional virtuosity is demonstrated by the atypical dome fragments, would have opted for a structure running such risks. We should examine the possibility that the meridional joints discernible in Knoll’s photograph did not run continuously along the main body of the dome, but were interrupted by bricks also arranged in arched courses. That would be possible if the bricks of the dome were arranged in a network of small interlocking segmental arches, suggestive of a fish’s scales. The problem of the convergence of these scales in the dome’s crown could be avoided by limiting them to a broad belt, above which horizontal brick courses take over (fig. 161). Such a structure would resemble closely the domes found in centralised mausoleums such as the ones at Split, and Side. Of these domes, the one covering the Mausoleum of Diocletian at Split is the best preserved and documented.450 If this reconstruction were correct, then the baptistery of St. Mary would constitute the second instance of a dome made of arched courses in Ephesos.451 That seems to suggest that this method of construction was not unique to the late antique Dalmatian coasts, but was further developed in west Asia Minor during the early Byzantine period. This development seems to have been so influential that the technique continued to be used, possibly until the late Byzantine times.452

162. St. Mary, cross-domed church. Detail of the pitchedbrick vault of the north side chamber.

4. Secondary Vaults of the Cross-domed Church

Having analysed and interpreted the vault fragments of the baptistery we now have a more or less complete – albeit hypothetical – picture of the monument’s original vaulting scheme. Examining the domed central hall, the groin vaulted bays next to its main entrances, and the barrel vaulted corridors of the ambulatory, we realize that the layout of vaults is used as a means of giving emphasis to certain spaces. Lofty and centralised vaults such as domes are crowning elements used to highlight the most important spaces of the monument; barrel vaults are merely meant to respond to the practical need of roofing lesser, ancillary spaces. A second conclusion regards the particular vaulting techniques employed. These techniques seem to deviate from standard practice: in the barrel vaults and groin vaults of the ambulatory bricks are laid on edge rather than radially; the dome itself was built with arched courses instead of horizontal ones.453

Due to the limited archaeological evidence for the main vaults of the domed St. Mary, our reconstruction in this particular church is based on our interpretation of its plan, and on comparisons with better-preserved churches.454 These same remains give us the only opportunity in our research to enter two fully preserved ancillary chambers, with their vaults almost intact. The latter also call for a change of method: our task here is not to reconstruct, but to observe and analyse. The Vaults in the Side Chambers The vaults found within the eastern piers, first demand our attention (fig. 162). The space within each of these piers is divided into a square anteroom and a rectangular chamber, which probably had an apse in its east end, facing the entrance. Barrel vaults covered both these rooms. Up to a certain height above their springing, these vaults are built with oversailing horizontal brick courses. Over this point, the fabric of the vault consists both of radial and pitched brick courses. These are combined in a way so artful, that we find ourselves wondering whether the purpose of this brick pattern was purely constructional (fig. 163).

449

See J. Heyman (1995), as well as Mainstone (1988, p. 165). F. Fasolo (1953, pp. 79–80 and 1956, fn. 12) was the first author to note that the dome fragments of the baptistery of St. Mary indicate the use of vaulting methods previously employed in the cupola of Diocletian’s Mausoleum, at Split (Spalato). 451 For a similar structure in St. John at Ephesos, see Chapter 3, Section 6. 452 H. Buchwald (1977, pp. 289–290) has observed such arched courses in the apse of the Lascarid church E at Sardis, something that indicates the perennial use of this technique in the region. 453 The degree to which this vaulting method limited the need for centering will be examined in chapter 7. 450

454

For this reason, this hypothetical reconstruction has to remain diagrammatic, omitting any information about the structural articulation of elements.

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163. St. Mary, cross-domed church, northeast pier and side chamber, cut-away axonometric (drawing by Nikolaos Karydis, 2009). This vault clearly demonstrates the construction method followed. Having built the lower portions with horizontal oversailing courses, the builders started from the two narrow ends of the space to be covered laying repetitively pitched courses of bricks against the bounding wall to the west and apse to the east. This must have been done without centering, with the builders relying (for temporary stability) purely on the adhesion between bricks and the fast-setting mortar, which they probably used. After a certain distance from the two ends had been covered, the courses laid on edge started to assume a curved tracing,455 and, at the same time, to alternate with courses placed radially. This alternation continued with pitched and radial courses interlocking along two diagonals, until the vault was closed at the centre with a square “plug” of bricks.456

The Broad Arches The broad arches that cover the passages through the four main piers have also survived intact (fig. 164). They consist of two concentric rings, each made of bricks of standard size set in a radial way.457 This arch form, encountered in St. John at Ephesos, and the baptistery of St. Mary, and reminiscent of eastern Roman Imperial practice, seems to be typical of monumental building both in late Roman and early Byzantine Ephesos. Further observation of one of these very well preserved arches reveals a complex structure (fig. 165). Comparing the two faces of the arch, we realise that they are quite different: in the face towards the nave the arch rings are of equal depth, whereas in the face towards the aisle the outer arch ring is half the usual depth and lacks the overlying brick course seen in the nave elevation.

455 The curved shape of courses, increasing the length of the mortar beds between them, has been interpreted by A. Choisy (1883, pp. 31–36) as the result of an effort to increase the adhesion between courses during the first phases of construction. The same author still provides us with the most complete and best illustrated overview of Byzantine barrel vaults made with brick courses laid on edge. He designates such vaults “berceaux construits par tranches verticales”. 456 This vault structure is identical to the one over the narrow corridors of the baptistery. The similarity between the two structures is puzzling, given the alleged chronological distance between them: the baptistery is

considered to be contemporary to the phase of St. Mary that preceded the domed church (see M. M. Parvis, 1945, p. 70). According to S. Karwiese this phase dates back to the late 5th century. The domed church, on the other hand, has been recently dated to the late 6th century (see S. Karwiese, 1999, p. 84). 457 Here, we also encounter a detail noticed in the blind arches of St. John at Philadelphia: the structure is covered by a single arched course of bricks laid with their surface against the arch extrados.

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164. St. Mary, cross-domed church, view of the barrel vaults over the passageways through the west piers.

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165. Ephesos, St. Mary, cross-domed church. Interpretive axonometric of the barrel vaults over the passageways of the west piers. Notice the local reinforcement of the barrel vaults at the side of nave (drawing by Nikolaos Karydis, 2009). The fact that the rear portion of the arch structure is weaker than the front one should not surprise us. The front portion of the arch carries far greater loads than the rear one since this side of the pier receives the weight of the major barrel vaults supporting the dome.

and a very rough interpretation of the plan, this cannot be trusted to give us the measure of the vaulting layout. The reconstruction by F. Fasolo, although diagrammatic and largely hypothetical, is much more credible as a guide towards future reconstruction efforts.459 It also makes clear that such efforts need to engage properly in formal comparison with churches with a scale, and an organisation of architectural space similar to the domed phase of St. Mary at Ephesos.

This last observation draws our attention to the primary vaults. Given the absence of tangible evidence, it is not possible to reconstruct their structure in detail. Still, it would be possible to make hypotheses concerning their schematic form on the basis of comparisons with analogous churches. Therefore, we will have to briefly deviate from the main topic of this chapter in order to sketchily reconstruct an architectural form in its entirety, a necessary step towards the investigation of St. Mary’s vaults.

- Firstly, the section proposed is characterized by extremely shallow proportions, which are never encountered in early Byzantine vaulted churches. Indeed, the piers are shown to be only 6.8m high, almost half of the nave’s width. Such a ratio is very far from the typical one. In the church of the Koimesis at Nicaea, for instance, the height of the piers used to be almost equal to the nave’s width. - Secondly, the windowless screens below the lateral arches contradict early Byzantine architectural practice. These are the result of the inexplicable decision to lift the roof of the aisles to an excessively high level, which makes the proportional relationship between the aisle width and height almost 2/5! - Thirdly, given that no less than three staircases were found on-site, the representation of St. Mary as a church without galleries is at least questionable. - Finally, the covering of all the vaults surrounding the dome by a common roof, with two enormous gables on top of the east and west elevations is yet another problematic point. 459 See F. Fasolo (1932, pp. 12–13, figs. 15, 16).

5. Reconstruction of the domed church F. Knoll’s reconstruction is so atypical stylistically as to puzzle someone familiar with early Byzantine ecclesiastical architecture.458 Based mainly on guesswork 458 My reasons for distrusting the reconstruction by F. Knoll (1932, p. 62, fig. 73), are the following:

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The Vaults of St. Mary at Ephesos flanking the apse of the early basilica are sufficiently preserved to allow us to establish the approximate level of the gallery floor, probably around 8.60m above the ground.465 Synthesizing all the above evidence, we can sketch the section of the domed church: Its main horizontal lines and their levels were respectively the cornice of the gallery floor, at 8.60m, the springing line of the major barrel vaults at 13.00m, and the springing of the dome at 19.00m above the ground (fig. 166).

Relevant churches vary considerably, making it difficult to find a group of comparable examples for the purposes of our reconstruction.460 Nevertheless, the cross-shaped nave of St. Mary, with the typical lateral cross arms barely noticeable, evokes a series of cross-domed basilicas such as the church of the Koimesis at Nicaea, Saint Nicholas at Myra, Saint Clement at Ankara, and, above all, Saint Sophia at Thessaloniki. These churches share a series of characteristics that also occur in St. Mary: the cross-shaped plan of the nave, the side chapels flanking the apse, and the massiveness of the piers.461

Secondary Vaults Having hypothetically determined the rough outline of the nave vaults we now move to the secondary vault pattern. In reconstructing the aisle vaults we ought to take into account the sequence of ten internal pilasters along the north and south walls of the basilica. It seems likely that these pilasters carried longitudinal arches, which, in their turn, supported a barrel vault running along the entire length of the aisles. Whether the latter sprang above the apices of the arches it is not certain. An alternative layout, with interpenetration between arches and barrel vaults, echoing the form of the aisle vaults of St. John at nearby Ayasoluk, cannot be totally excluded (fig. 115). A similar, but slightly steeper vaulting layout might have been used in the galleries.466

Nave vaults Comparisons with the above churches suggest the existence in St. Mary of a dome pierced with windows over the crossing, surrounded by two barrel vaults over the east and west cross arms and by two broad arches over the lateral cross arms. The proportional relationship between nave width and the height of the springing of the dome at Thessaloniki, Nicaea, Myra, Ankara, ranging from 1:1.5 to 1:1.6, may be used to establish the level of the major vaults of St. Mary. If the proportions of the Ephesian monument were not resolutely different, then its dome must have sprung approximately 19.00m over the ground and the supporting barrel vaults at a height of circa 13.00m.462

The nature of the vaults covering the esonarthex cannot easily be determined.467 Still, the series of engaged ionic columns and pilasters placed against its walls clearly shows that this space was divided into five bays. This architectural articulation and the parallel with St. Sophia at Thessaloniki suggest that the esonarthex was covered by five groin vaults.

With its four main piers reaching such a height, it seems unlikely that St. Mary did not have galleries.463 The latter’s existence is also indicated by no less than three staircases found on site.464 Of these staircases, the ones 460 A year after the discovery of St. Mary, J. A. Hamilton (1933, p. 51) interpreted the building as the first domed basilica. Some years ago, M. F. Castelfranchi (1999, p. 90) claimed that the “rebuilding of St. Mary at Ephesos was done following models from Constantinopolitan ecclesiastical architecture (…) and aimed to create an Ephesian Hagia Sophia”. The first attempt to distinguish examples of churches that would be more convincingly compared with St. Mary was made by R. Krautheimer (1986, p. 249). His classification of the church alongside the church at Korykos (Meriamlik), the east church of Alahan Monastery, and the church at Qasr Ibn Wardan, overlooks the two most important characteristic of St. Mary: its cross-shaped dome nucleus, and the central location of its dome. H. Buchwald, (1994, pp. 25–27) interprets St. Mary as a typical cross-domed basilica and compares it to the church of the Koimesis at Nicaea, Saint Clement in Ankara, and Saint Sophia at Thessaloniki. 461 A series of differences between St. Mary and the cross domed Anatolian basilicas make their comparison less obvious than the one between the Ephesian church and St. Sophia at Thessaloniki. Even though examining the examples from Anatolia can be useful in revealing some of the three-dimensional aspects of the Ephesian church, it is really Saint Sophia at Thessaloniki that can give us the best insight into the latter’s original form, and vaulting layout. 462 F. Knoll (1932) suggested that the dome sprang 14.5m above the ground. This is very low. It makes the nave look too shallow in cross section. The ratio between the height of the dome cornice and the nave width is almost 1.2. In our examples, regardless of whether the basilicas have galleries or not, this ratio never falls below 1.5, and, in most cases, including St. Sophia at Thessaloniki, is found to be 1.6. 463 Cross-domed basilicas often have galleries. The only cross-domed churches without galleries seem to be the Church of the Archangels at Sige, and the church of the Koimesis at Nicaea. 464 A U-shaped staircase 1.00m wide is found in the northeast corner of the atrium, and, as we have seen, two other staircases flanked the apse of the early basilica. Even though these staircases probably belong to the earlier phase of St. Mary, there is no reason to believe that they

Discussion All the above observations lead us to a more or less plausible, but schematic reconstruction of the domed phase of St. Mary. A new suggestion about how the church may have looked like in section is shown in figure 166. This reconstruction differs from the ones that preceded it. It tends to inscribe St. Mary in an architectural development typical of the period of the 7th

stopped being used after the erection of the domed basilica. Indeed, as S. Karwiese (1999, p. 84) has shown, the entire eastern part of the early basilica remained in use after the building of the domed St. Mary, and communicated with it. Therefore, the twin staircases flanking the early apse, could also have served to offer access to the galleries of the domed basilica. 465 Our observations concerning the two east staircases are based on the survey of F. Knoll (1932, p. 36, fig. 34). In both staircases, traces of three flights of steps survive. One had to climb another five flights of steps to reach a point exactly above the staircase’s entrance. In total, there must have been 33 steps, with an average height of 26cm. Therefore, the topmost landing must have stood at a height of 8.60m above the ground. 466 See Chapter 3, Section 3. 467 Even less is known about the vaults of the western galleries, where the quantity and diversity of possible reconstructions can defeat the most courageous researcher.

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166. Ephesos, St. Mary, cross-domed church. Reconstructed cut-away axonometric (drawing by Karolina Vasilikou, 2009). and the 8th centuries.468 Whereas the Austrian reconstruction is unconvincingly peculiar, and F. Fasolo’s reconstruction remained too diagrammatic, my efforts resulted in the representation of St. Mary as an archetypal domed basilica, very similar to St. Sophia at Thessaloniki.

piers) played a major role in this diagrammatic reconstruction, while almost all the dimensions (i.e. height of spaces, vault levels) are justified by archaeological evidence. Quite unlike those attempted eighty and fifty years ago, this reconstruction unites both formal and archaeological clues harmoniously.

It would not be entirely unfair to criticise my reconstruction for its deviation from my usual methodology, primarily based on the analysis of vault fragments. In this particular case, I was compelled to rely on formal comparisons, principally with St. Sophia at Thessaloniki. Yet, this reconstruction is also faithful to St. Mary’s existing fabric. Several elements (staircases,

6. Development of Vaulting Techniques St. Mary gives us the unique opportunity to compare surviving vaults or vault fragments from the two first phases of the monument. Comparison between brick sizes and layouts is essential in drawing information about the broad tendencies that marked the development of vaulting techniques during the age of Justinian. At the same time, the earliest of the vault fragments, belonging to a time

468 The domed St. Mary is not necessarily a product of this period. H. Buchwald (1984, p. 221) suggests that an early appearance of a cross domed basilica at Ephesos would be justified by the role of the city as a major “political, economic, and religious centre” of the 6th century.

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The Vaults of St. Mary at Ephesos period in which no standard vault construction method had been established, giving the builders a great liberty to improvise. But, it is difficult to believe that such use of brick, characterised as it is by such expertise and constructional virtuosity, was improvised. We should consider the possibility of influence from earlier vaulting traditions that had not been used before in a monumental scale. This scenario explains both the high quality of construction of these vaults, and, at the same time, the reason why they lacked the rationality and uniformity often characterising large-scale construction.

when most architectural monuments were timber-roofed, probably reveal to us one of the forms in which brick vaulting was introduced to ecclesiastical architecture of west Asia Minor. Therefore, these early fragments may be helpful in discussing the origins of vaulting practice in this region.

The Changing Dimensions of Bricks and Mortar Beds The vault fragments examined suggest that in the passage from the early to the domed phase of the church, there has been a dramatic change in the size, and, in particular, the thickness of bricks used for vaulting. Early bricks appear to be twice as thick, but not as large as the late ones.469 On the other hand, the mortar beds in the early phase of St. Mary, with an average height of 3cm, are considerably thinner than the ones of the domed phase, whose height regularly reaches 5cm. It therefore seems that the early practice to build vaults consisting predominantly of brick, and only a limited amount of mortar was at some point modified by a fairly consistent tendency to use larger bricks, and to increase the amount of mortar between them.

The diversity of brick layouts in early vaults can be studied in the two side chapels flanking the apse of the early phase of St. Mary. In each of these chapels and the staircases next to them, no less than four different layouts are observed. The comparison with the side chapels of the domed phase of St. Mary is very telling: there, in spite the division of space into two chambers, only one brick layout occurs throughout the structure. These late vaults seem to have been built at a time when vault construction had largely been rationalised and standardised. The improvisatory expertise of local builders, sought in the early phase of St. Mary was then no longer required.

Brick Layout in Vaults: From Invention to Standardisation

Origins of Vaulting Techniques Auguste Choisy (1883, pp. 156–157) believed that the origins of early Byzantine vaulting of cities such as Ephesos are not only to be found in the Greco-Roman architecture of the east, but also in an “eastern school of vault construction employing [crude] bricks without centering”. A. Choisy might have expressed himself more strongly, and, perhaps, more specifically, had he been able to compare the early pitched-brick vaults of St. Mary with the crude brick vaults of Karanis and Soknopaiou Nesos, discovered by archaeologists some forty years after the publication of L’ Art de Bâtir chez les Byzantins. J. B. Ward-Perkins has been the first scholar to compare this vaulting tradition with Byzantine practice.470 The early phase of St. Mary totally justifies this comparison. Indeed, studying the forms of the modest, shallow vaults within the staircases of St. Mary, we cannot help remarking their similarity with the pitched brick vaults in Karanis.471

Other broad tendencies in vault construction between the two main phases of St. Mary can be deduced from the comparison between the layouts of vaults. The brick layouts of the earlier vaults seem to be very inventive. Indeed, they do not seem to have been used in earlier monuments in the area. The brick layout consisting of radiating arcs, such as the one studied in the remains of the north side chamber of the early basilica seems to be unique to St. Mary. All these early vaults are also quite complex. For instance, the staircase vaults avoid the repetition of a brick pattern. Instead, diverse ways to set the bricks have been tried during construction, giving the shells of these vaults a composite appearance. By comparison, later brick layouts are far more simple and rational. They seem to rely on two logical concepts: standardization and the repetitive use of pitched bricks. This technique can generate very complex vault surfaces without requiring the use of centering. This is, perhaps, the reason why such brick layouts became one of the marks of standard vaulting practice during the times of Justinian.

This similarity could be purely coincidental. After all, St. Mary is not the only monument in Asia Minor where similar vaults are encountered.472 Nor is it likely that such late roman vaults are unique to Karanis.473 This ancient

The inventive, complex brick layouts of the earlier vaults are indicative of techniques that had probably ceased to be in use by the time the vaults of the domed basilica were built following more rational and standardised brick patterns. The artfully conceived, and diverse brick patterns of the early vaults are likely to characterise a

470

See J. B. Ward-Perkins (1956, pp. 91–93, fig. 20 and 1981, p. 365, fig. 238). In both cases, we find the same diagonal arrangements and herringbone patterns of brick courses. 472 A. Choisy (1883, p. 102) observed similar vaults with diagonal courses in the Roman walls of Magnesia on the Maeander. 473 According to J. B. Ward-Perkins, (1956), p. 91, the only reason for his referring specifically to Karanis is that “this is the only comparable site to have been carefully dug and recorded”. 471

469 Indeed, the average brick in the early basilica measures 6 x 32 x 32 cm, whereas most of the bricks found in the domed basilica measure 4.5 x 36 x 36 cm.

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474 According to A. Khatchatrian (1971, p. 17), “in Mesopotamia (…) and Egypt, vaults and domes made of crude bricks, built without centering and originating in the early antiquity, were still being constructed in the first centuries of our time”. Cf. G. R. H. Wright (2000, p. 143).

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identified, could be further subdivided into subcategories with regard to geometrical form. Such a strategy, primarily grouping together similar structures as opposed to forms gives a more interesting overview of the variety of techniques early Byzantine builders had at their disposal. This original typological strategy can eventually help to find the criteria guiding the builders to choose between the techniques known to them.

Chapter 7 Typology of Brick Vaults: Construction and Centering

In my survey, I have distinguished three types of vault construction, each one with the capacity to generate diverse forms. The first type, and perhaps the most familiar with today’s builders, consists of vaults with radial brick courses. The second type of vault structure, very often encountered in west Asia Minor, includes vaults built with bricks set on edge (pitched bricks). The third type, maybe the most peculiar to our modern eyes, groups together vaults with arched brick courses. The frequency with which this seemingly atypical technique seems to be employed, in conjunction with the importance of the vault forms it generates, make us consider its discovery in west Asia Minor a major development in our knowledge of early Byzantine architecture.

1. General Considerations In concluding our overview of the use of vaulting, it may be well to present a typology of methods of constructing arches and vaults as exemplified by the main churches of west Asia Minor. Looking back at the vaults that have been examined so far, we realise that vaults with the same geometrical form do not necessarily have the same brick structure. What seems like a repetition of a standard vault form often dissimulates a number of different structures. For example, we have recorded at least four different barrel vault structures, and at least three ways to build a spherical pendentive.

I have thus classified the vaults according to their brick pattern. I believe the latter to be one of the best indications of how the vaults were constructed. Having said that, there is an obvious limit to our ability to trace the exact manner in which bricks and mortar were assembled in a vaulted form fifteen centuries ago. One of the most obscure aspects of this building process concerns the use of temporary formwork. The simple observation of a vault structure is no longer considered sufficient to deduce whether centering has been used in its construction.477 Nevertheless, I consider centering to be one of the key aspects of Byzantine vault construction. A typology of vaults would not be complete without briefly referring to indications concerning the type of the scaffolding, formwork, and templates used together with each vault structure.

Vaults of the same geometrical form (i.e. domes, semicylindrical vaults, groin vaults) can have a wide range of uses. Barrel vaults, for instance are used both to cover small, secondary spaces (ambulatories, chapels, corridors), and as major nave vaults. The range of uses of a specific vault structure, on the other hand, is far more limited. For example, as A. Choisy and J. B. WardPerkins had observed, vaults made of pitched bricks, whether semi-cylindrical, or groined are fairly consistently used to cover relatively small spans;475 on the other hand, vaults made with their bricks laid radially are often subjected to important loads, or cover wide spans. These observations make us wonder whether form should after all be the sole criterion for categorising vaults.476 An alternative to the distinction between different vault geometries would be the identification of types of brick patterns in vaults, with each pattern corresponding to a particular construction method. Such types, once

2. Vaults with Radial Brick Courses: the Primary Vault Structure The radial placing of bricks and their separation by radiating beds of mortar has been considered the standard method of arch and vault construction in early Byzantine architecture.478 Various remains and vault fragments in west Asia Minor reveals that this technique, so typical of arch construction, has been very often employed in the construction of broad arches or barrel vaults, semidomes,

475 According to A. Choisy (1883, p. 41), “the Byzantines avoided applying this method [i.e. pitched brick vaulting] to vaults subjected to violent and sudden forces. They would have hesitated to build a bridge arch with bricks laid on edge…” Cf. J. B. Ward-Perkins (1958, p. 58). 476 A. Choisy (1883), to whom we owe the first Byzantine vault typology, tended to give particular importance to construction techniques in his classification. He first makes the distinction between two broad categories: vaults built on centering, and vaults built without temporary supports. Within each category, the vaults are grouped in types according to their form. This typology, made in a time when classification by genera and species was considered very important in the field of the rapidly progressing natural sciences, is the model for my own effort to establish vault types.

477

It is interesting to see how our doubts concerning the early Byzantine use of centering have increased instead of diminishing. This tendency becomes apparent if one compares three of the main treatises on Byzantine vaulting: A. Choisy (1883, pp. 31–56), W. S. George (1913, p. 43), and R. Mainstone (1988, pp. 202–208). 478 See C. Mango (1978, p. 11).

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167. Ephesos, St. John, detail of barrel vault incorporated in the buttress between the transept and the baptistery. pendentives, and – probably – domes.479 Even in cases of vaults where a different technique is used, one always finds a small part made of radial bricks. This indicates the familiarity of early Byzantine craftsmen with this method of building, and, perhaps, their awareness of its profound rationality, probably the reason why this particular technique is still widely used today.

individual bricks set at a steep slope, or entire portions of vaulting), from falling before the structure is locked into position.481 It is reasonable to expect that early Byzantine builders would have probably responded to these needs through the use of centering.482 Broad Arches and Barrel Vaults with Radial Bricks

The creation of a semi-cylindrical or spherical roof by placing successive horizontal rows, or rings of bricks at a gradually increasing inclination from the horizontal is more difficult than one might suspect. In the process of building, one soon realises the need for a device to control the emerging vault shape, as well as a means to maintain the bricks roughly true to the curvature.480 If the vault in question is a barrel vault, or an exceedingly shallow dome, there is also a need for temporary support preventing the unfinished parts of the vault, (be it

Judging from its recurrent use in almost all the churches we examined, the process of setting bricks radially to form semi-cylindrical vault shells must have been one of the most common Early Byzantine vaulting methods in west Asia Minor. The reasons that led builders to adopt this particular method may be found by observing the 481

On the other hand, hemispherical domes made of radial bricks can in principle be constructed without centering. Indeed, during the construction of such a vault, “each completed horizontal ring will itself function as a circular arch and prevent the inward collapse of the incomplete vertical arches.” See R. Mainstone (1988, p.165). 482 Curved templates would have served the double purpose of shaping and supporting such a vault during construction. We should therefore consider the erection of such formwork as a very important – but unfortunately obscure – part of the construction of vaults with bricks laid radially.

479 The application of this specific technique to hemispherical vault construction, so common elsewhere, has not been entirely proved by archaeological finds in this particular region. 480 This need is more important in spherical vaults, which are curved in two directions.

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Typology of Brick Vaults: Construction and Centering context of such barrel vaults. These tend to form part of the primary structural system.483 It is vaults built with radial bricks that carry the domes, spanning the long distance between the main piers. Such barrel vaults also form part of the pier structures, carrying and distributing important dead loads. Therefore, this particular layout of bricks was probably considered as the one better suited to bridge wide spans efficiently and to carry important loads (fig. 167). The articulation of the intrados of a barrel vault with radial bricks has many points in common with the one of a typical brick masonry wall: its bricks are also laid in a horizontal direction, with their vertical joints staggered, in neat common bond. The only difference between wall and vault, besides the curvature, regards the bed-joints, which are tapered in the curved structure.484 A frequent variation to this technique was to divide the barrel vault into two superimposed vaults of smaller thickness.485 This practice must have had a series of advantages. By limiting the length of the tapered radial joints it avoided their excessive widening, and thus, limited the proportion of mortar to brick along the extrados. More importantly, this same vaulting method also allowed building the vault in two stages, reducing the weight imposed on the formwork. The latter only had to carry the first, inner ring of bricks. Once these bricks were locked into position they gradually started to “function” structurally, serving as permanent formwork for the outer ring, relieving the original centering from carrying the weight of the entire section of the barrel vault.486 Finally, it may well be that such “coupled” barrel vaults were stronger than normal ones with the same thickness. This, however, remains to be proved and assessed.487

168. St. Mary, cross-domed church, southwest pier, typical barrel vault with radial brick courses (drawing by Nikolaos Karydis, 2009). The stability of these strategically located barrel vaults did not rely only on a coherent and robust structural fabric, but also on their proportions. Barrel vaults interconnecting couples of piers, as the ones that still survive in St. Mary, were given a massive thickness, often around 0.70m, a size representing almost 1/5th of their span (fig. 168).488 The fact that the thickness here is largely superior to the safety limit shows that the builders had taken into account both the excessive compressive and shear stresses to which these particular barrel vaults were subjected.489 Barrel vaults bridging the span between main piers and carrying the central vault were also given an important thickness, often ranging between 0.80 and 1.00m. In these cases, the ratio between the diameter and the thickness, ranging between 1/15 and 1/12, is also above the safety limit. Given the fact that these particular barrel vaults were meant to counteract the lateral thrusts of the dome base, their soffit width must have also been critical. In such barrel vaults, expected to act as buttresses, the soffit width was never inferior to 1/4th of the span of the dome they supported.490 An important soffit width secured the barrel vault against outward lateral bowing under the side thrusts of the dome. The impact of these thrusts on barrel vaults or broad arches with an insufficient width can still be seen in the north and south major arches of Hagia Sophia.

483 In the site of St. Mary, the solitary barrel vaults with radial bricks are the ones over the passageways in the main piers. In the baptistery of St. Mary, a series of vault fragments (documented by F. Knoll, 1932, pp. 48–49) confirm that all the vaults linking the main piers were made of bricks set radially. Fragments of similar vaults were observed in St. John at Ephesos by H. Hörmann (1951, pp. 92–93, tables XXI, XXII). These fragments belonged to the barrel vaults spanning the distances between the main piers. The intact barrel vault just outside the north cross-arm of St. John at Ephesos is not an exception to this rule. This barrel vault covered the passageway through a buttress linked with one of the piers of the church, and can therefore be considered inscribed within the primary load-bearing system. The broad arches of St. John at Philadelphia, partly surviving, are yet another indication of the use of this particular technique to construct broad arches and barrel vaults that would either resist important loads, or cover significant spans. 484 In particularly thick vaults, the tapering of mortar joints can lead to the creation of exceedingly wide jointing along the extrados, and to increase the proportion of mortar to brick in this particular area. This excessive amount of mortar would risk increasing the degree of structural deformation due to plastic flow in the initial stages of construction. However, this does not seem to have deterred Byzantine builders from constructing thick barrel vaults with exceedingly long radiating courses. 485 Such “composite” barrel vaults are found in St. John and St. Mary at Ephesos. 486 Although the problem of exceeding the formwork’s bearing capacity might seem trivial to us, we ought to take into account that it proved to be a major worry during the building of Hagia Sophia. See Procopius, I. i. 65–71. 487 J. P. Adam (1994, p. 158–164) has suggested that arches made of several concentric tiers of voussoirs are stronger than ordinary arches. Auguste Choisy (1883, p. 109) had noted that, in some “composite” barrel vaults, the outer ring is limited to a portion of the vault

corresponding to the footprint of an overlying wall mass. The role of such rings, often built with a smaller proportion of mortar, and hence less deformable, is to relieve the inner one, often weaker, by distributing the loads to the side walls. Such a structure can be observed in the surviving barrel vaults within the piers of St. Mary at Ephesos. 488 Given that according to empirical thumb rules, the thickness of a barrel vault ought not to be smaller than 1/20 of its diameter, this ratio is completely acceptable. See J. Heyman (1995, pp. 20–22). This is confirmed by R. Mainstone (1988, p. 169). The thickness of the examples of barrel vaults he mentions is never below the limit of 1/20th of the span. 489 According to R. Mainstone (1988, p. 165) vaults connecting piers together are subjected to important shear stress. 490 Thus, in Ephesos, barrel vaults with a minimum soffit width of 3.40 and 4.00m carry domes with diameters ranging between 12.30 and 13.00m respectively. In both Sardis and Philadelphia, the major barrel vaults are tunnel-like. Their soffit widths represent almost a third of the span of the dome.

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Early Byzantine Vaulted Construction in the West Coastal Plains and River Valleys of Asia Minor Examining the transverse section of the great church, we can clearly distinguish the important outward inclination of the south arch.491 Having investigated the shells of these barrel vaults, we ought now to turn our attention to their immediate surroundings, starting by examining their backing and its structural role. Their entire intrados would have been exposed.492 The extrados, on the other hand, when not entirely enveloped by a wall’s mass, would have been covered up to a certain height by a superimposed fill.493 This fill, sometimes consisting of mortared rubble levelled by brick bands, performed a vital structural role as abutment, counteracting the lateral thrusts of the barrel vault.494 Indeed, not only did it prevent the lower part of the vault from bowing outwards but also, by weighting on the supports, it helped to direct the thrusts down to the ground.495

169. Interpretive model simulating barrel vault construction and showing the form of centering used in the radial setting of bricks (model by N. Karydis, 2003–4).

The springing of a wide barrel vault seldom went unnoticed. It was marked by stone cornices, strong enough to provide a firm, rigid seating for the vaults, unlikely to move, or crush locally under the significant thrusts to which it is subjected.496 Special care was frequently taken to connect the cornice blocks firmly together. In St. John at Ephesos, for instance, the constituent blocks were cramped together with pairs of metal staples and mortared.497 However, in other cases, as for instance in St. John at Philadelphia, the lack of bond between blocks shows that these cornices were sometimes seen more as levelling courses rather than as tensile chains.

such stone courses would have constituted the only elements within a masonry mainly consisting of brittle bricks and fresh mortar to be capable of supporting the heavy, long beams of a temporary timber structure. But what was the nature and exact purpose of this timber structure? Unfortunately, no evidence exists for its configuration other than the provisions (cavities, projecting cornices) near the feet of the barrel vaults to support horizontal timbers.499 These could guide us to imagine this temporary timber structure as a kind of flying wooden centering, on which the overlying barrel vault was constructed. The earliest available depictions of flying formwork, dating back to the 16th century, show frames following the principles of trussed construction.500 As L. Lancaster has noted, these principles had been known since the Roman times. Therefore, their use in early Byzantine Asia Minor should not be excluded. A sequence of similar frames, covered by planks, could have well been used as a means to define the curve of the major barrel vaults (figs. 169, 170).501

Probably, the outward projection of stone “springers”, often emphasized by an elaborately moulded undersurface, did not only respond to aesthetic considerations, but also served a secondary, constructional purpose: the one of supporting the scaffolding necessary for the building of the barrel vault.498 Indeed, the stone blocks of 491 See R. Mainstone (1988, p. 96, fig. 115) and Robert Van Nice’s detailed drawing in A. ù. Çakmak and R. Mark (1992, pl. 4). 492 The intrados of a brick barrel vault would often be one of the most important parts of the interior of the church. Its surface would have been covered either by multi-coloured mosaic or by frescos. I have discovered small traces of mosaic, consisting of blue and white tesserae, in one of the surviving major barrel vault fragments of St. John at Ephesos. Hans Buchwald (1981, pp. 309–311) has found numerous patches of fresco on the surviving vaults of St. John at Philadelphia. 493 This meant that a semi-cylindrical barrel vault would not have easily been distinguished from the exterior of the church. 494 As we have seen, there are many ways to construct such reinforcement. In Sardis and Philadelphia, this is made of mortared rubble reinforced by bands of stronger material: solid brick masonry at Building D, and ashlar masonry at St. John. In St. John at Ephesos, on the other hand, the backing is made of brick, the same material as the vault shell. 495 See J. Heyman (1995, p. 51). 496 Remains of such springers, consisting of marble blocks, and forming parts of long, continuous cornices marking the baseline of vaults have been examined in the baptistery of St. Mary at Ephesos (F. Knoll, 1932, p. 48, fig. 49), in St. John at Ephesos (H. Hörmann, 1951, p. 95, fig. 14, I), and in St. John at Philadelphia. 497 See L. E. Butler (1992, p. 64). 498 See J. B. Ward-Perkins (1958, p. 61). The role of projecting courses of stone as supports for scaffolding seems to be confirmed by the remains of St. John at Philadelphia. The cavities found in the lower

portions of the major barrel vaults of this monument, probably traces of the use of scaffolding, or flying centering, are always located just above a string course of stone blocks. 499 Such cavities are found in St. John at Philadelphia. Fragments of projecting cornices are found in St. John at Ephesos. 500 For an illustration showing the flying centering used in the construction of the principal arches of St. Peter’s in Rome, see R Mainstone (1988, p. 170, fig. 197). Such depictions have influenced researchers in their hypothetical reconstructions of late antique flying centering. A very convincing example occurs in L. Lancaster (2000, p. 779). For a speculative description of the type of centering that could have been used in Hagia Sophia, see G. R. H. Wright (2000, p. 142). 501 On the other hand, we should also take note of a series of indications betraying the attempt in St. John at Philadelphia to limit the amount of centering used in the construction of barrel vaults. The setting of bricks at a flat inclination throughout the lower portion of the barrel vaults may well reveal a tendency to limit the extents of temporary support. Indeed, in this structure the latter would have only been absolutely necessary in the construction of the crown of the barrel vault, the only area where the steep inclination of bricks could not be avoided. This area, much smaller than the entire intrados, could possibly have been built with the aid of smaller, movable templates. The use of such devices could explain the irregular shape of the vault, which could also, however, be attributed to deformations and settlements.

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170. Sardis, Gymnasium (2nd century AD and later), broad arch consisting of two superimposed rings of radial bricks. Several details deserve attention: the ashlar masonry wall projects inwards in order to provide footing for the centering used during construction. The removal of the formwork created a recess in the springing of the arch. Note the different thickness of the arch rings (to be compared with fig. 167) and the use of a stone voussoir in the key. The massive ashlar masonry walls, combined with the use of mortared rubble interspersed with brick masonry band are elements of a late Roman local tradition that would later be adopted by early Byzantine builders in this area.

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171. Miletus, Baths of Faustina (2nd Century AD). Detail of lateral niches, showing barrel vaults made of flat chips of stone set radially.

160

Typology of Brick Vaults: Construction and Centering There are numerous precedents of barrel vaults with radial bricks in late Roman (Imperial) buildings in Greece, and west Asia Minor.502 Early examples of this technique in west Asia Minor include the vault covering Tomb 2, in the Sanctuary of Artemis at Sardis (1st century AD), the numerous surviving vaults of the 2nd Century Gymnasium Complex at the same city (fig. 170), the vaults over the lateral niches of the Serapeum at Pergamon (early 3rd century AD), as well as the vaults of the Harbour Baths at Ephesos.503 The vaults of the Roman Baths at Nicopolis in Epirus attest the use of similar techniques in Greece. It seems that this manner of vaulting had already known a long process of development before the early Byzantine period. At Miletus, one can see something of the process that marked the introduction of radial brick barrel vaults in the region’s monumental building practice. The Baths of Faustina, built in the 2nd century, incorporate early barrel vaults built with radial bricks, side by side with other vaults, made of flat chips of stone also laid radially (figs. 171, 172).504 This amalgam demonstrates the gradual, almost timid introduction of bricks in barrel vault construction as a lighter substitute to stone, as well as the fact that the radial setting of voussoirs is a technique that precedes the introduction of brick. From 2nd century Miletus to 6th century Ephesos, there are four centuries during which barrel vaults with radial bricks kept being built and developed. It is perhaps the maturity reached through this development that justifies the frequent use of this type of vault as an essential feature of the structure in the early churches of west Asia Minor.

172. Miletus, Baths of Faustina. Detail of barrel vault with stones set radially. The construction of brick pendentives seems simple in principle: it consists of filling the space between the broad arches, or barrel vaults, with bricks forming conical courses (i.e. courses curved in plan and with a gradually increasing inclination from the horizontal). In practice, however, this construction must have been quite complex, because of the generic mismatch between the edges of a spherical pendentive and the extrados of the barrel vaults meant to support it.506 Our survey identified three ways of dealing with this problem: the method used in Philadelphia consisted in distorting the spherical shape of the pendentive structure, in order to make its intrados engage tangentially with the faces of the barrel vaults. A second solution, attested by a fragment in Sardis, was to separate barrel vaults and pendentive with a wedgeshaped border made of radial bricks, (charfrein) maintaining a smooth transition between the two structures. A third way to deal with the same problem was to provide the barrel vaults with a sloped face (“skewback”) for the pendentives to lie against. The variety of remedies to this problem possibly indicates the experimental character of pendentive construction during a period when the techniques of covering rectangular bays by spherical vaults had not yet entirely matured.

Pendentives and Spherical Vaults Built with Bricks Set Radially The methods employed in building the massive spherical vaults that constitute the crowning elements of the design of most of our churches remain relatively obscure (fig. 173). The pendentive remains at Ephesos (fig. 81) and Philadelphia (fig. 126) are the only spherical vault fragments we have identified, and constitute the most important evidence for the way in which spherical vaults were built.505

502 Although the development of such vaults took place during the late Roman period, it would be wrong to interpret it as an influence from metropolitan Roman practices. In Italy, during the Imperial period, the main vaulting material has been Opus Caementicium as opposed to brick. 503 See H. Dodge (1987, p. 107) for the tomb at Sardis, J. P. WardPerkins (1981, p. 277) for the Serapeum at Pergamon, and F. Fasolo (1956, pp. 15 – 17) for the Harbour Baths at Ephesos. 504 For a richly illustrated description of the layout of the complex see F. Yegül (1992, pp. 290–294). A reference to the vaults of the Baths occurs in J. B. Ward-Perkins (1981, pp. 294–295). 505 Given the usual similarity between pendentive and dome structure in other early Byzantine buildings, it would be reasonable to expect that the domes just above these pendentives had been built in a similar way. Although the following paragraphs focus on a specific type of pendentive construction, the techniques they examine are likely to reflect dome construction as well.

506

The reasons for this incompatibility have been analyzed in the context of our examination of the surviving pendentives of St. John at Philadelphia.

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173. Sardis, Building D, Hypothetical Reconstruction of typical spherical vault with bricks laid radially (drawing by Nikolaos Karydis, 2009). of small, moveable templates, (and, perhaps, using a string attached to the centre of curvature as a guide) the pendentives reached the crown of the barrel vaults with the only scaffolding necessary being the platform for the builders to stand upon. After that, there were two main ways to complete the vault: by creating a shallow dome, which constitutes part of the same spherical surface as the

It is doubtful whether the construction of the pendentives required any centering. The latter could be dispensed with because the intentionally gentle inclination of the courses was not enough to make them slip from the mortar beds below them. But, it is also the shape of the pendentives, with its double curvature that makes them self-supportive during construction: each of their completed horizontal rings functions as a segmental arch preventing their collapse.507 Thus, by laying course on course with the aid

analyzed by P. Sanpaolesi (1971), p. 8, who states: “these selfsupportive vault structures (strutture voltate autoportanti) did not require temporary centering during construction, but rather supported themselves as they gradually grew, by virtue of their brick layout (apparecchiatura) and their geometrical form.”

507 In pendentives such as the ones of St. John at Philadelphia we find all the characteristics (brick layout, spherical shape) of self-supportive dome construction. The principles of this method of vaulting have been

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174. Rome, Baths of Caracalla (3rd Century AD), octagonal Nymphaeum. Notice the remains of the primitive pendentive in the center, to the left of the upper arch. pendentives (fig. 173), or, alternatively, by forming a circular base consisting of stone blocks, and raising a hemispherical vault upon it.

pendentives in an attempt to put the spherical vaults examined above in perspective. The technique of merging the angles of a square or polygonal room to create a circular base for the seating of a dome is found in western Imperial monumental building of the 3rd and 4th centuries (fig. 174).509 Pendentive-like structures are also encountered in 2nd century funerary architecture in Rome.510 Still, in these cases we are only dealing with ill-defined approximations to the spherical triangle, made mainly of concrete and faced with brick.511 It would be exaggerated to claim that these particular examples influenced pendentive construction in Early Byzantine Ephesos and Philadelphia.

The question regarding the origins of the building of spherical triangles with radial bricks as means of transition from a rectangular or square plan to the base of a spherical vault is a crucial one. Indeed, this technique was destined to determine the character and the development of Byzantine church Architecture for more than a millennium.508 Although this problem cannot be resolved in the present context, this would be a good occasion to call attention to some earlier examples of

508 This enormous subject can only be summarily addressed here. The following paragraph, rather than aiming to resolve the problem completely, hopes to give the general directions that further research into this question could follow. Further information about the origins of the dome resting on pendentives can be found in K.A.C. Creswell (1969, pp. 450– 471), who calls attention to early Middle Eastern examples of this practice. For a survey of the origins of the pendentive dome in Christian architecture, see E. Langlotz (1955, pp. 35–41).

509

Primitive pendentive-like structures are found in the remains of two 3rd century domed octagonal halls in the Baths of Caracalla. An illustrated description of the pseudo-spherical triangles in these halls occurs in D. S. Robertson (1983, p. 252, fig. 106). 510 See G. Pelliccioni (1986, p. 40, fig. 16). 511 According to R. Mainstone (1988), p. 162, “there is no evidence [in Imperial Architecture in Rome] of the use of the true independent pendentive to carry a dome of any size over a square bay”.

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175. Sardis, Bath-Gymnasium Complex, hall “BHC” (2nd century AD and later). Detail of pendentive remains on northwest corner. On the other hand, the West Baths of Gerasa, in Syria, built in the 2nd century AD, include three cases of domes on pendentives made of dressed stone that clearly foreshadow early Byzantine vaulting practice in Side, in South Asia Minor.512 This rare Syrian example indicates that pendentive domes had been known in the Eastern provinces of the Roman Empire, much before the form was used in Hagia Sophia.513 One of the to answer practice of brick. The

Bath-Gymnasium Complex in Sardis may illuminate this problem. This hall still preserves significant remains of relatively flat, but, otherwise, well-formed pendentives made entirely of horizontal brick courses (fig. 175).514 The dating of these pendentives is far from being certain, as the structure to which they belong underwent many alterations and renovations after its initial construction, probably in the late 2nd century AD.515 It is possible that these features reflect a vaulting practice known in west Asia Minor from as early as the late Imperial period. On the other hand, the same features may have well been the marks left by an early Byzantine renovation of the Roman

questions that future research should attempt is when and where this oriental vaulting pendentive construction was translated into central domed hall (BHC) of the Imperial

514

The hall and its pendentives were first shown to me by Professor Marcus Rautman in June 2008. Axonometric drawings of the hall in question occur in F. Yegül (1992, figs. 334, 362). This particular fragment was first published by A. Choisy (1883, p. 160, table XIV, 2) who saw in it an excellent fusion of Roman and Oriental vaulting practices. 515 The reasons for the generally accepted date of the Bath-Gymnasium Complex in Sardis are summarized in F. Yegül (1976, p. 174, fn. 7). Clive Foss (1976, pp. 20, 35–36) dates the complex to the early 3rd century AD.

512

Indeed, the 2nd century pendentives at Gerasa are identical both in form, and in structure, to the pendentives supporting the domes of the Martyrium south of the Cathedral at Side. See A. M. Mansel (1978, p. 264, fig. 294), J. B. Ward-Perkins (1970, p. 338, fig. 218), and P. Sanpaolesi (1971, p. 19, figs. 57, 58). 513 S. ûurþiü (1992, p. 28) claims that Hagia Sophia at Constantinople was the first building to use such a pendentive dome. Still, there is evidence for earlier uses of such domes in Gerasa, and Ravenna (Mausoleum of Gala Placidia).

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176. Ravenna, “Mausoleum of Galla Placidia” (5th Century AD), interior view looking towards the pendentive dome which is decorated with one of the finest and best preserved late Antique mosaics. The dome is made of radial bricks laid in concentric courses. The stars of the mosaic seem to follow the same pattern. The figures decorating the pendentives have been identified as the four living creatures of the Apocalypse.

complex. This could be an attempt to replace the previous, late Roman ceiling (probably a barrel vault) of the rectangular hall BCH by a shallow dome on pendentives, a characteristic aspect of early Byzantine construction. Early examples of similar forms occur rarely both in Italy and in Asia Minor, in 5th century buildings, while its employment became systematic during the time of Justinian (figs. 176, 177).516

3. Vaults with Pitched Bricks: the Secondary Vault Structure In the vaulted and aisled basilicas of Ephesos, next to the major vaults covering the naves, there was an additional 516 Indeed, similar, well-formed pendentives start to occur regularly in the 5th century, mostly as parts of shallow, pendentive domes. An early example of this form occurs in the 5th century mausoleum of Gala Placidia in Ravenna (see R. Krautheimer, 1986, pp. 181–183). Remains of pendentive are also found in the south chapel of the Cathedral of Aphrodisias, published in R. Cormack (1990, p. 82).

177. Aphrodisias, early Byzantine basilica (5th century AD), south side chamber. Detail of pendentive remains, based on photographs published in R. Cormack, 1990 (sketch by N. Karydis, 2006).

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Early Byzantine Vaulted Construction in the West Coastal Plains and River Valleys of Asia Minor network of vaults with a secondary structural role. Their construction seems to have called for vaulting techniques largely different from the ones used in the major vaults covering the nave. A fundamental difference was that construction here did not start from a horizontal plane, as in vaults with radial brick courses, but from the vertical faces of major walls, supports, and arches of the primary structural system. These elements formed the points of departure of successive vertical or steeply inclined rings of bricks laid on edge. The fact that each individual course of the vault could function as a circular arch meant that the vault was self-supportive during its construction. Thus, the building of such vaults did not require any temporary support other than the small, moveable templates keeping individual bricks in place until each arched ring was complete.

178. St. Mary at Ephesos, cross-domed church, east side chambers, typical barrel vault built with pitched bricks (sketch by Nikolaos Karydis, 2006).

The vault fragments examined in Ephesos suggest that this economical vaulting technique was employed in a wide variety of vault forms, including both barrel and groin vaults. The division of vaults in arched “slices” whose shape could be easily adjusted while construction was in progress, made this vaulting technique ideal for roofing secondary spaces with irregular, or unconventional plans.517 On the other hand, pitched-brick vaulting was limited to vaults with a secondary structural role, where a potential failure would not undermine general stability. If this particular technique was adopted frequently, this was because of its flexibility and minimum centering requirements, rather than the strength of its products.518 Pitched-brick Barrel Vaults Judging from the vault remains of the churches of Ephesos, pitched-brick vaulting has been mainly applied in small barrel vaults, with a secondary role (fig. 178). Such barrel vaults are found in the aisles of St. John, the side chambers of the domed phase St. Mary, as well as the corridors of the baptistery of St. Mary. Although the main body of these vaults consisted of bricks set in pitched courses, their lower portions, as well as their middle parts, were executed with horizontal brick courses. This composite structure reflects the tendency in early Byzantine west Asia Minor to reduce the need for centering without, however, entirely abandoning the conventional technique of setting bricks radially.

179. A stage in the construction of two typical pitched brick barrel vaults. Above: longitudinal sections; below: plans (sketch by N. Karydis, 2004, after A. Choisy, 1883). This seemingly peculiar combination of techniques can be explained by taking into account the construction sequence that was probably followed in one the barrel vaults covering the chambers flanking the west apse of the St. Mary. Having completed the setting of a series of horizontal courses forming the lower portion of this vault, the workmen must have gone on to start laying pitched courses simultaneously from the two narrow ends of the space to be covered. With the repetitive building of almost vertical brick rings, each one lying against the other, construction gradually moved towards the centre of the space (fig. 179). There, construction changes, with the

517 Indeed, as J. B. Ward-Perkins (1958, p. 61) has eloquently suggested, “pitched-brick vaulting offers a maximum of detailed variation and allows vaulting to be applied in circumstances that might well defeat the more conventional builder”. 518 According to A. Choisy (1883, p. 41), the reluctance to use this technique in vaults with a wide span, or vaults subjected to important loads is not only found in west Asia Minor, but characterizes Byzantine construction in general. There seems to be a controversy regarding the actual structural behaviour of pitched-brick vaults. A. Choisy believed that such vaults were very rigid and, as long as the mortar ensured a firm connection between their courses, they behaved as monoliths, and did not impose significant horizontal thrusts to their supports. On the other hand, J. Heyman (1995, p. 49) claims that the layout of courses in a vault does not affect the amount of lateral thrust transmitted to its abutments.

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Typology of Brick Vaults: Construction and Centering brick barrel vaults are to be found.520 It seems that in cities along the Roman-Parthian frontier, such as DuraEuropos, around the 1st century AD, this vaulting technique was translated into fired brick, a more durable material.521 This development was marked by the combination of a typically Roman building material (fired brick) and an essentially Middle-Eastern technique (pitched-brick vaulting).522 It is in this form that this technique made its first appearance and in Greece, and in west Asia Minor.523 The most famous early application of this vaulting method in Asia Minor occurs in the barrel vaults of the substructures of the basilica at Aspendos, in Pamphylia, built in the 3rd century.524 A good example of pitched-brick vaulting in Greece occurs in the barrel vaults of the radiating bays of the Rotunda (St. George), at Thessaloniki, built around 300 A.D.525 By the time the vaults at Aspendos and Thessaloniki were built, pitchedbrick barrel vaults had already developed most of the characteristics we found at early Byzantine Ephesos, notably the combination of horizontal courses at the feet, and vertical ones along the crown of the vaults. Therefore, when the master builder of St. Mary decided to cover the side chapels by successive vertical courses instead of horizontal, radial ones, he was following an ancient vaulting practice, which, while still rare in the western provinces in the Empire, had been established in west Asia Minor for at least three centuries.

bricks set radially to form a portion that tapers upwards (fig. 178). This component limited the area between the two ends of the pitched-brick construction that had to be filled-in with a plug of bricks, and helped to lock the entire vault into position. None of these building stages necessitated an extensive use of centering. The radial setting of bricks in the feet of the vaults was possible without temporary support as the inclination of the bricks was not steep enough to cause the bricks to slip. In the central portion of the vault, the steeper the inclination of horizontal courses became the more their length decreased, limiting the need for temporary framework to the minimum. The rest of the construction, based on a repetition of self-supportive vertical rings must have only required a limited use of formwork. Indeed, thanks to the horizontal courses at the feet of the vault, the length of the vertical rings was reduced, facilitating their temporary support with the aid of small, moveable templates. We therefore realize that the introduction of horizontal, radial courses, seemingly paradoxical in a structure that does not require centering, is in fact meant to facilitate building without timber formwork. This highly flexible technique facilitated the creation of complex vaults generated by the interpenetration between semi-cylindrical surfaces. Unless such vaults are built with bricks laid on edge, they require extensive and complicated centering. An example of such a complex pitched-brick barrel vault occurs in the aisles of St. John at Ephesos. In this case, construction of the barrel-vaulted constituents must have started simultaneously from the faces of the wide, transverse arches in the ends of each bay, and from the smaller, longitudinal side arches over pilasters and columns. The smaller, transverse vaults and the main, longitudinal one interlocked along pronounced groins whose sequence must have given this hybrid vault structure an appearance different from the one of a typical barrel vault.

The foregoing overview of the origins of pitched-brick barrel vaults may leave the reader with the impression that this aspect of Byzantine vaulting practice in Ephesos is characterised by an extraordinary conservatism. This impression, however, overlooks two facts: that the early Byzantine builders both in Asia Minor and Constantinople were the first to use pitched-brick vaulting in a consistent way, limiting it to secondary vaults;526 and, mainly, that they were the first to broaden the range of applications of this vaulting technique by employing it in domical groin vaults of various shapes.

The technique of pitched-brick vaulting was reserved to secondary barrel vaults, with a small span, which were in many ways different from the major ones both in thickness, and in the way in which they were incorporated in their surrounding structure. In secondary barrel vaults, the shell, often consisting of half-size bricks, was much thinner than the one of a primary barrel vault with the same span.519 Also, unlike major barrel vaults, secondary ones were often completely enveloped by masses of mortared rubble, something that meant that their faces and extrados were almost never exposed.

520

H. Dodge (1987, p. 114) claims that the earliest known examples of pitched-brick vaulting in mud-brick “appear to be in the third millennium BC at Saqqara in Egypt”. A. Choisy (1883, p. 154) has observed the use of similar mud brick barrel vaults in the storage sheds near the mortuary temple of Ramses II, which is dated to the 13th century BC. 521 H. Dodge (1987) suggests that the earliest known examples of pitched-brick barrel vaults in fired brick occur at Assur, Seleucia on the Tigris, and Dura Europos in the early 1st century AD. 522 Ch. Delvoye (1976, p. 235) states: “Anatolia combined fired brick, coming from Italy, with the technique of pitched-brick vaulting without centering, originating in Syria, Mesopotamia, and Egypt”. 523 According to H. Dodge (1987, p. 114), the earliest pitched-brick barrel vault in Asia Minor occurs at Izmir, in the substructures of the North Basilica of the Agora. 524 See J. B. Ward-Perkins (1970, p. 276, fig. 176). 525 See G. Penelis et al. (1992, p. 133, fig. 82) and J. B. Ward-Perkins (1958, pp. 89–90). 526 Indeed, in earlier periods, pitched-brick vaulting was used indiscriminately both in major barrel vaults, (such as the ones in St. George at Thessaloniki, between the main piers), as well as in secondary ones. According to A. Choisy (1883), the Byzantines reduced the use of this technique because of its structural disadvantages.

The technique of pitched-brick vaulting is known to have originated in ancient mud-brick construction in Mesopotamia and Egypt, and it is there that the earliest, and most distant precedents to early Byzantine pitched519 Indeed, at St. John, the narrow barrel vaults interconnecting the piers had a span of 3.00m and were approximately 0.70m thick. Although the barrel vaults over the aisles of the same church had a wider span, their thickness was a mere 0.30m.

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180. Constantinople, Hagia Sophia, outer narthex, pitched-brick groin vaults.

Pitched-brick Domical Groin Vaults

The construction of the vaults of this type in Ephesos started from the creation of an arched foothold consisting either of arches, or walls with their tops given an arched shape. These arches and/or walls were provided with a sloping face towards the vault. This preparation of the surrounding structure to accept the vault is particularly visible in the baptistery of St. Mary at Ephesos. The vault proper was built with pitched brick courses laid parallel to the sloping faces of each side, and interlocking along the diagonals. This construction technique could be adjusted to a wide range of bay plans. The examples studied confirm this: the domical groin vaults of the baptistery of St. Mary had been probably built over oblong and slightly irregular bays, while the one of St. John was built on a triangular plan.

Groin vaults made with pitched bricks were frequently used in the Early Byzantine churches of Constantinople (fig. 180). My research at Ephesos identified fragments of two vaults that could be considered as approximations to groin vaults: one in the ambulatory of the baptistery of St. Mary, and one, built on a triangular plan, in the southeast corner of the baptistery of St. John (see fig. 98). These vaults, like most early Byzantine vaults of a similar kind, must have deviated from the common geometrical definition of a groin vault.527 This was not only because their lines of intersection (or groins) were blunt, but also due to the fact that their central portion must have been elevated to a higher level than the one of the apices of the four bounding arches. The constituent interpenetrating surfaces of these vaults were curved in two directions, and merged towards the top of the vault, forming shallow domes, hence the designation domical groin vaults.

The two domical groin vaults surveyed must have originally performed a secondary structural role. Their spans were quite limited, in both cases less than 4.00m, and none of them seems to have supported an upper floor. The thickness of their main shell, hardly superior to the size a standard brick, is the one proper to a secondary vault. Such light vaults must have transmitted limited thrusts to their supports: walls and arches. Their particularity is that, unlike Roman cross vaults, which required a four-point support system, they distributed

527 R. Krautheimer’s (1986, p. 518) definition of the term groin vault as “the vault formed over a square (sic) bay by the interpenetration of two barrel vaults of equal diameter and height” needs to be reviewed in the light of countless Byzantine examples – such as the groin vaults of the outer narthex of Hagia Sophia – which deviate from it. For a description of these vaults see A. Choisy (1883, p. 52).

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Typology of Brick Vaults: Construction and Centering early Byzantine vaults. The resulting vaults must have differed from the standard barrel vaults, pendentive domes, and hemispherical domes, only in structure. Their plastering after completion left no visual indication of their constructional difference.

both their weight and thrusts more uniformly to their bounding perimeter.528 In justifying his reconstruction of the Church of the Thermae at Hierapolis, Paolo Verzone made the following comment: “cross vaults are quite rare in Asia Minor and are mostly employed in solitary bays”.529 The early Byzantine churches at Ephesos confirm this. Groin vaults seem to have been used in rare cases, especially in irregularly shaped ancillary spaces, which lacked parallel walls necessary for the construction of a barrel vault.530 Yet, this vaulting technique should not be seen merely as a way to deal with “problematic” areas of a church, but also as a means to emphasize a spatial unit, or to accentuate the division of a long corridorial space to individual bays.

The main reason for the adoption of this unusual vaulting technique must have been the need to limit the centering required. Still, this reason does not suffice to explain the difference between these vaults and more conventional pitched-brick vaults, which, as we have seen, also have a reduced need for timber formwork. Yet, it is quite possible that the method of laying bricks in arched courses went a step further from pitched-brick vaulting in this field, perhaps allowing the elimination of centering altogether. Indeed, in pitched-brick vaults, each of the vertical rings needed temporary support until it was completed. The fact that the length of the rings, and, therefore, the size of the templates required for their formation were proportionate to the span of the vault, made this technique impracticable when it came to sizeable vaults. On the other hand, the builders must have known that the more the length of these rings was reduced the smaller this support needed to be. Vaults with arched courses helped to minimize the length of the brick courses. This made this technique the most efficient way to divide enormous vaults into miniscule, self-supportive arches to an extent that conventional pitched-brick vaulting was incapable of.

4. Vaults with Arched Brick Courses: Ephesian Examples of a Rare Vaulting Practice. The types of vault structures examined so far are not unique to west Asia Minor, but should be considered as a commonplace of standard early Byzantine architecture in the Aegean Coastlands of Greece and Asia Minor.531 However, in the churches of St. John and St. Mary at Ephesos, there is also a range of vault fragments that must have belonged to atypical vaults, constructed in a way that seems to break with standard early Byzantine vaulting practice. The dome of the baptistery of St. Mary, the pendentive domes over the side-chambers and the staircases flanking the east apse of the same church, as well as the two west pendentive domes of St. John, all belong to this group.

Even though vaults with arched courses occupy a marginal place in the manuals of late Roman and early Byzantine architecture, when they are not altogether omitted, this particular vaulting method seems to have had a lasting influence on monumental building at Ephesos. Indeed, while in St. John and St. Mary there are hardly any remains from domes constructed with radial brick courses, at least three fragments of domes built with arched brick courses have been recorded. This seemingly atypical vaulting method has perhaps been one of the principal ones used in early Byzantine Ephesos. Our knowledge concerning the applications of this vaulting practice is not yet complete.532 The following paragraphs examine the whole range of vault forms generated with this method in Ephesos. They thus hope to cover a lacuna in our knowledge of what seems to have been one of the main vaulting methods used in an important urban centre of the early Byzantine Empire.

The distinctive mark of these vaults is that they consist of arched brick courses. My definition “arched brick courses” corresponds to courses curved in two directions: such courses follow both the curvature of the vault as well as the curvature of an independent pattern of smaller arches within the vault. These arches have a length, which is always shorter than the circumference of the vault – something that, as we will see, has a great effect on the method of construction. Such “arched courses” are either assembled in a single repetitive sequence, or grouped to form wedge shaped, scale-like units. Following this unusual technique, the builders of Ephesos were able to generate the entire geometrical range of

532

The pioneering publication by Piero Sanpaolesi (1971, p. 3–23) – the most important to date – was the first one to identify most of the main domes built with arched courses and to offer illustrations for the majority of them. This publication underlined the fact that these particular domes do not require centering, but did not explain sufficiently in what way the arched courses contributed to that. Also, it failed to identify the Ephesian application of this vaulting technique to other vaults besides domes, as well as to notice the arched brick courses of the western domes of St. John at Ephesos. Still we should be grateful to P. Sanpaolesi for an excellent survey of the little-known East Mausoleum at Side, and for showing that the limitation of centering has had a continuous influence on dome construction, from the Greek Archaic Period to the Neoclassical one. An account of the evolution of this vaulting technique, focusing on Byzantine building, and demonstrating its later use in Middle and Late Byzantine architecture, occurs in H. Buchwald, (1977, p. 289).

528

See A. Choisy (1883, pp. 130–135). See P. Verzone, (1956, p. 40). 530 Indeed, the ambulatory of the baptistery of St. Mary, and the corner rooms of the baptistery of St. John have both irregular shapes, both the sacrificial by-product of the design of the main bays. 531 For instance, the Basilica B, at Philippi, in northern Greece, seems to have included a series of pitched-brick domical groin vaults; St. George at Thessaloniki still preserves several instances of pitched-brick barrel vaults; The same vault types are not at all rare in Constantinople, a city whose early Byzantine monuments, such as Hagia Sophia or St. Eirene, provide us with abundant examples of barrel vaults and pendentive domes built with bricks laid radially. The export of these vault types to the eastern provinces of the Byzantine Empire is attested by the church at Qasr Ibn Wardan, in north Syria. 529

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Early Byzantine Vaulted Construction in the West Coastal Plains and River Valleys of Asia Minor Barrel Vaults Built with Arched Brick Courses Until now, arched brick courses (i.e. brick courses with a double curvature, and a length shorter than the circumference of the vault) have been thought to occur mainly in domes and semidomes.533 Still, in Ephesos, there are two surviving barrel or pseudo-barrel vaults that satisfy the definition I have given to vaults built with arched brick courses. Indeed, the vaults that cover the two staircases of St. Mary consist of inclined courses with a double curvature (fig. 181). Each of these courses departs from the latter’s springing line and follows a diagonal route until it reaches the apex. There, it interlocks with the corresponding courses of the opposite side. The repetition of this form throughout the vault produced an atypical herringbone pattern, very rarely encountered in barrel vaults. The barrel vaults over the staircases of St. Mary consisted of two different superimposed shells, each of them being one normal brick in thickness. Diagonally arranged arched courses occur only in the inner shell. The outer one has its bricks set in the conventional radial manner, with excessively thick radiating mortar joints between them (10cm approximately). Over this double shell there was a heavy, solid fill of mortared rubble, which raises the structure up to the stepped surface required for the superior level of stairs. The constructional difference between the two shells betrays both the way in which the vault was built as well as the qualities attributed to each structure by early Byzantine builders. The intricate vaulting pattern of the inner shell must have had limited need for centering. Indeed, the diagonal slices in which it was divided were entirely self-supportive during construction. Each new course, thanks to its inclination, could lean against the previous one as the vault progressed, guaranteeing the stability of bricks, which was further assisted by their adhesion with mortar. Even if this was not enough to keep the bricks in place without support, the function of each course as a circular arch also prevented it from collapsing. The small circumference of these courses, representing two thirds of the circumference of the courses within a typical pitchedbrick barrel vault of the same size, meant that they could be built on a small, portable timber template.

181. Ephesos, St. Mary, columnar basilica, south side chamber, barrel vault with arched brick courses (drawing by Nikolaos Karydis, 2009). Domes on Pendentives and Pendentive Domes built with Arched Brick Courses Because of their shallow form and their particular brick pattern, pendentive domes constructed with annular rings of bricks required extensive formwork. Each of the horizontal rings of such a vault can be – theoretically – considered as self-supportive, due to its function as an arch once it is completed.534 But, as long as the ring remained incomplete, its bricks would remain unstable unless they were kept in place by some kind of support. In large vaults, the size of this timber support, as big as the dome’s circumference, would have made its handling difficult as construction progressed. By replacing the annular concentric brick courses by shorter courses, shaped and set so as to function as self-supporting arches during construction, the early Byzantine builders of Ephesos managed to limit the size of the timber templates needed. This technique, based in the division of large domes in small, arched segments, helped to dispense with centering, regardless the diameter of the dome (fig. 178).

It is very probable that the inner shell of these barrel vaults was built first as a permanent support for the building of the outer shell. The increase of thickness resulting from the addition of the outer radial bricks must have significantly strengthened the vault. The constructional difference between the two shells is an echo of their different roles: the inner one serves primarily as centering, whereas the outer shell has as its main role the distribution of loads to the side walls.

533

534

See H. Buchwald (1977, p. 289).

170

See R. Mainstone (1988, p. 165).

Typology of Brick Vaults: Construction and Centering

182. Ephesos, St. John, nave, reconstruction of spherical vault built with arched brick courses (drawing by Nikolaos Karydis, 2009). A first step in reducing the length of the brick courses of a dome could have been the substitution of the standard method of the annular, horizontal courses with radiating, arched ones. Yet, such a pattern of vaulting occurs only once in West Asia Minor, in the pendentive dome fragment examined in the north side chapel of St. Mary.535 The structure of this unique pendentive dome illustrates the tendency to limit the size of the units to which a shallow spherical vault is divided, and, hence, the centering required.

St. Mary at Ephesos. These were vaults of enormous size, made up of arched courses that were grouped, as we have noted, in wedge-shaped units resembling the scales of a fish. These blocks are shaped in such a way so as to interlock perfectly. This helps to minimize the length of their arched courses. The contrast here between the huge circumference of the vaults, reaching about 12.50m and their disproportionately short arched courses, whose circumference did not exceed 2.00m is very intense. The individual bricks of each of these courses could be first laid against a moveable template. Once the course was complete, it started to function as a segmental arch supported on the topmost courses of the two scales below. Its template could then be removed and used in the next course. Thus an entire dome could be built with a minimum amount of small timber supports.

The influence of this tendency on dome construction in early Byzantine Ephesos is demonstrated by the remains of spherical vaults in St. John and the baptistery of 535 In the construction of this particular vault, the timber template required to hold in place the bricks of each individual course would have been much smaller than the one used in a conventionally built spherical vault (i.e. one with annular rings). We have not been able to identify any other similar dome structures in early Byzantine architecture. Yet, methods of vault construction based on the formation of similar radiating courses seem to have been regularly employed in semidomes. A. Choisy (1883, p. 72) has observed semidomes built with radiating brick courses in the Baths of Nicomedia. According to H. Buchwald (1977, fig. 23), this same technique has been employed in parts of Middle Byzantine semidomes with a composite structure, such as the ones in the Myrelaion (presently “Bodrum Camii”), and in the church now called “Ahmet Pasa Mescidi”, both at Constantinople.

This idiomatic vaulting layout inscribes the spherical vaults of Ephesos in an early vaulting practice whose rare applications seemed until now to be scattered in the east Mediterranean region. Indeed, the similarity of the dome construction techniques followed in St. John and the baptistery of St. Mary, with the ones followed at the Mausoleum of Diocletian at Spalato (built in the late 3rd century AD), and at the east Mausoleum at Side have already been noted. The study of similar spherical vaults

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Early Byzantine Vaulted Construction in the West Coastal Plains and River Valleys of Asia Minor at Ephesos represents the first instance in which multiple uses of this particular technique are concentrated in a single place. This is likely to suggest that Ephesos, and perhaps the area of west Asia Minor under its influence, has been one of the rare places where this method of vaulting was developed locally. The quantity of the examples found, on the other hand, seems to indicate that the building of domes with “arched” courses became, at some point, as popular as the standard, conventional method of dome construction using concentric, annular rings.

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masses of brick and mortar. The concentration in fragments and their interpretation did not always resolve all the reconstruction problems. My new representations of the churches still involve a certain amount of speculation. However, this should not distract us from the fact that a new methodological tool has been developed with a potential use in the reconstruction of a wide range of early Byzantine vaulted churches.

Conclusions

St. John at Ephesos The church of St. John at Ephesos is perhaps the best example of modular construction in west Asia Minor. Indeed, a look at the excavated remains of the church shows that the nave of this enormous, complex monument consisted of a sequence of structural units.536 However, the full impact of this compartmentalisation on the organization of architectural space of the monument can only be correctly assessed through the visualisation of its vaults, which has been the object of the 3rd chapter of this book. Throwing light on both the form and structure of the vaults, this reconstruction has revealed the existence of constructional differences between the vaults over the nave and the ones over the east part of the church. This reconstruction has the potential to provide new evidence on the construction phases of St. John.

The beginning of my exploration of the vaulted churches of west Asia Minor was marked by the impression that their dilapidated remains could only offer limited information about their original structure. Still, as the survey progressed, the very incompleteness of these remains was found to expose many aspects of their construction. It soon became apparent that further close observation not only served the analysis of the existing fabric but also revealed new evidence for graphic reconstruction. This realization opened the way for a new documentation of construction techniques and a new exploration of structural forms. As this book is nearing to its conclusion, it would be good to summarize its contribution to the study of early Byzantine construction in west Asia Minor. This summary starts with the results of my new reconstruction of the vaulting pattern of each church, a part of their structure that remained enigmatic until now. With our knowledge enriched by a new understanding of their vaults, we can move on to draw conclusions regarding the general construction principles of vaulted church architecture in the region. The understanding of these principles leads us to identify those specific aspects that distinguish west Anatolian vaulted construction from other currents of Early Byzantine church construction. But, before we give an account of all these conclusions it seems appropriate to refer briefly to the particular reconstruction methodology that led to these results.

The discovery of three new pendentive fragments (fig. 183) makes it possible to reconstruct the building with pendentive domes over the bays of the cross arms, and a hemispherical dome on pendentives over the crossing (fig. 184).537 The new evidence confirms the recent, tentative reconstruction of A. Thiel, and the hypotheses of P. Verzone.538 This reconstruction shows that, despite the modular character of the structure, the crossing bay maintained its role as the centre of the composition. My reconstruction was the first to focus on the brick layout of vaults. Thus, it revealed a major structural difference between the west cross arm, and the transept. The west pendentive domes were built with arched brick courses forming patterns reminiscent of the dome of the octagonal mausoleum at Spalato (Split). The east domes were built with the standard system of circumferential courses. This is not the sole constructional difference between the west and east parts of the building.539 These

1. The New Reconstruction Methodology The new reconstructions were largely based on a new reading of the ruins. This approach relied on the interpretation of carefully identified vault fragments. For example, the reconstruction of entire nave vaults was guided by the observation of the bottom courses of pendentive fragments, and the particular way in which these courses meet the supporting arches. Even fragments that do not belong to vaults proved to be important. For instance, the shape of the surviving backing of vaults, in some cases, revealed the form of their missing shell. The interpretation of these fragments would have been impossible without systematic comparisons with construction details found in coeval, surviving churches such as St. Eirene, and H. Sophia at Constantinople. Evidence provided by comparable examples elsewhere proved to be essential for the interpretation of fragments that, isolated, seemed to be little more than amorphous

536

In this particular church, as well as in the ones at Philadelphia, Sardis and Hierapolis, the design is based on the repetition of a structural unit consisting of four piers, which carry brick arches surmounted by a spherical vault. Indeed, the first reconstruction of the monument by H. Hörmann (1951), had given R. Krautheimer (1986, p. 242), the impression that “…the spatial units, rather than emanating from the center in a fluid movement, stand by themselves”. 537 The aisles of the church where covered by a composite vaulted surface generated by the interpenetration between a wide, longitudinal barrel vault and smaller, transverse ones. The gallery, on the other hand, was probably covered by uninterrupted, semi-cylindrical vaults springing above the level of the lateral arches. 538 See A. Thiel (2005, p. 110), and P. Verzone (1965, p. 609). 539 Indeed, both the brick walls and the stone piers of the transept are noticeably different from the corresponding elements in the west cross arm. As H. Plommer (1962, p. 122) has noted, in the nave, the change in construction accompanies a change in design. Different capitals, column bases and cornices have been employed in the two parts of the building. There is also a change in the number of columns per screen, from three columns, in the east part to four columns in the west one.

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183. Ephesos, St. John. Table showing pendentive fragments A, B, and C, and their current location in the site. The reconstruction of the nave vaults (upper right corner) was based on photographs of fragments that no longer survive (drawings by Nikolaos Karydis and Karolina Vasilikou, 2009).

184. Ephesos, St. John the Theologian, reconstructed axonometric (drawing by Karolina Vasilikou and Nikolaos Karydis, 2009).

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Conclusions

185. Ephesos, St. John, pre-Justinianic church and baptistery, reconstructed plan. Justinian seems to have replaced the west cross arm of this church with a long nave. This intervention altered the layout of the church, transforming the centralised building into a cruciform basilica. differences indicate that the vaulted church of St. John was not built in one stage, incorporating walls of the earlier timber-roof basilica, as A. Thiel recently suggested,540 but in two phases.541 The vaults examined show that the impact of these phases on the structure of the monument has been more important than originally thought.

The first phase of vaulted construction seems to precede the age of Justinian (fig. 185).542 It probably included the transept and the chancel of the present church, and had a west cross arm of equal length to the other cross arms. This hypothesis seems to be confirmed by Procopius (V. i. 6), who refers to a shorter church (“ȕȡĮȤȪȞ IJİ ȩȞIJĮ”) that was later “remodelled” by Justinian (“ȝİșȘȡȝȩıĮIJȠ ȝİȖȑșȠȣȢ țĮȚ țȐȜȜȠȣȢ”). The present location of the baptistery provides further proof for this hypothesis: its main axis would align with the narthex of the church with

540

See A. Thiel (2005, p. 110). H. Plommer (1962, p. 124) was the first to suggest that the vaulted church was built in two phases and to date the first of these to an unspecified time earlier than Justinian. 541

542

See M. Büyükkolanci (2000, p. 68), for a speculative dating of this first phase of the vaulted church to the period of Justin the 1st (518–527 A.D.).

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187. Philadelphia, St. John, reconstructed axonometric (drawing by Karolina Vasilikou and Nikolaos Karydis, 2009).

186. Sardis, Building D, reconstructed axonometric (drawing by Nikolaos Karydis, 2009). a Greek cross plan. On the other hand, this axis does not seem to correspond to any of the features of the present church. To what extent the first vaulted phase was completed before the intervention of Justinian, we cannot say. Still, the nature of this intervention is well known. It consisted in replacing the either damaged or incomplete west cross arm by a longer, twin-bayed and twin-domed basilica.543

St. John at Philadelphia Although the remains of this church include some of the best-preserved vault fragments in the region, the reconstruction of its vaults has been hindered by the dilemma between pendentive domes and hemispherical domes on pendentives.545 This problem was resolved by focusing on the two well-preserved vault fragments over the north piers. The manner in which the pendentive courses spring from the extrados of the arches is typical of pendentives carrying hemispherical domes.546 This realization led us to visualize the vaults surmounting the bays of the building as hemispherical domes on pendentives (fig. 187).547

Building D at Sardis The absence of fragments from the vaults of Building D has hindered its reconstruction. My understanding of it would have remained incomplete had I not realized that the vault core on top of the southeast pier, and the shape of the bays could offer indirect evidence for reconstruction. This new evidence suggests that the vault pattern of the building consisted of two identical pendentive domes over the two rectangular bays (fig. 186). From each domed bay, broad arches extended sideways. The previous reconstruction of the building with domes on pendentives built on an oval plan has to be reviewed.544

The form and brick layout of the vault remains betray the construction methods followed. The current survey was the first to note the geometrical irregularity of all the vaulted surfaces, and the setting of most bricks in them at a “flat” inclination. These characteristics are indicative of a “free-hand” method of construction, in which the emerging shape of vaults is controlled by the builder’s skill and judgement rather than by expensive and timeconsuming timber centering.

While the pendentive domes of Building D are missing, the vault backing and the pier cores have been preserved. These components, originally concealed, feature reused architectural elements taken from Hellenistic and Roman buildings, as well as masonry made of fieldstones, mortar and brick. This composite, large-scale structure, tells us a lot about early Byzantine construction. It symbolizes the tendency to abandon the delicate architectural vocabulary carved in stone in favour of one dominated by voluminous supports carrying heavy vaulted roofs made of brick and mortar.

The current work of reconstruction in Philadelphia was not limited to the missing vaults. A series of details in the remains of the church gave us a rare insight into the façade articulation. The main features of the north façade, 545

H. Buchwald (1981, p. 301–318) was in doubt to visualize the vaults over the two bays as pendentive domes or as domes on pendentives. 546 The vault pattern of this building, consisting of hemispherical domes on pendentives, is different from the one in Building D. This may be surprising given the similarities between the plans of the two buildings. 547 Important questions remain open. The exact form of the hemispherical domes (with or without windows, ribbed or not) is uncertain. It remains in doubt whether the church was provided with an apse or terminated in a straight wall. Its original length is also unknown. Only further excavations – an unlikely project, due to the buildings occupying the site – could clarify the situation.

543 The association of the nave of the building with Justinian and Theodora is proved by the Imperial monograms on the capitals. 544 A reconstruction along these lines has been suggested by H. Buchwald (1984, p. 211). The same reconstruction occurs in the “official” reconstruction drawings of the building in the archives of the Archaeological Exploration of Sardis.

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Conclusions The understanding of these tendencies is essential in gauging the development of church architecture in the west coastlands of Asia Minor during the early Byzantine period.

pilasters, niches hollowed into the wall, and blind arches surmounted by dogtooth friezes, seem to foreshadow the richness and playful character of Middle Byzantine church elevations.548 Assembling all these features in a drawing for the first time proved essential for visualizing the external appearance of the monument.

2. Principles of Vaulted Construction

St. Mary at Ephesos

The examination of the remains of the vaulted churches in west Asia Minor has revealed the nature of their building materials, the reasons for their availability and use, and their distribution in the region. Observing the dilapidated remains, it has also been possible to study the construction of load bearing elements and vaults. The following paragraphs will summarize the general characteristics of these structures, insisting on the parameters that influenced their form and the disposition of the materials in them.

The vault fragments from the two main phases of St. Mary had failed, until now, to attract the attention they deserve. These fragments are too small and scattered to give us a complete picture of the church. Still, their examination can form the basis for the reconstruction of individual vaults. This survey gives us the chance to study some unexplored aspects of west Anatolian church vaulting: its origins, and development during the early Byzantine period. The earliest fragments formed the basis for a revised reconstruction of the secondary vaults of the first building phase. New discoveries include pendentive domes consisting of radiating arched courses, as well as shallow barrel vaults, built with diagonal courses with their bricks laid on edge. The current research thus revealed peculiar techniques, which seem to deviate from standard early Byzantine vaulting practices.549 The surviving vaults of the late phase, on the other hand, known from previous research, seem to have had a more commonplace structure.550

Building Materials Dressed stone and marble, rubble, bricks, and mortar constitute the main building materials.552 The use of these materials seems to have been based on their load-bearing capacities. Dressed stone and marble, the most expensive materials, were often reserved for elements that were called on to carry especially heavy loads. Brick, a cheaper solution, seems to have been an all-purpose material, whose lightness made it ideal for vaults. Rubble, a material readily available everywhere, is often encountered mixed with mortar in secondary walls and inert fills.

The comparative examination of these fragments illustrates the development of vaulting techniques during the period separating the two phases of the church. The comparison between the early, atypical and varied vault patterns, and the more “normal”, late ones, seems to indicate a passage from inventive, artisanal techniques to standardized ones.551 However, the vault fragments of St. Mary are not numerous enough to confirm this hypothesis, which may, nevertheless, prove useful in the survey of other churches.

Although the above hierarchy often guided the choice of materials it did not always determine it. Within this logic there was room for considerable variation and change among regions and individual sites. The flexibility in the use of materials aimed to make the best possible use of the possibilities and resources each site offered. Taking all the regional variations into account we can draw conclusions about the distribution of building materials in west Asia Minor. The use of stone is found in all regions, but it seems to be more extensive in the area of Hierapolis (fig. 188). On the other hand the variety of decorative stones seems to increase in coastal sites like Ephesos. The use of brick seems to be more frequent closer to the coastlands, while it tends to disappear as we approach the highlands of Phrygia.

The new body of drawings, published in this volume, record the existing structure of the churches and represent their missing parts. Besides collecting information about the construction and form of individual churches, my research also used these churches as case studies for the exploration of general tendencies in vaulted construction. 548 Still, my survey has not found any proof for the thesis of M. F. Castelfranchi (1999, p. 97), who attributes these features to a later remodeling of the building. 549 The current research in the early vaults of St. Mary discovered new evidence for the vaults of the baptistery. Pitched brick barrel vaults seem to have covered its lateral corridors, while each of the north and south bays were probably covered by groin vaults. The central vault, a hemispherical dome, consisted of arched brick courses, probably arranged in a network suggestive of a fish’s scales. 550 Their semi-cylindrical form and the mixture of radial and pitched brick courses in their fabric reflect the use of the same vaulting methods as the ones found at Philippi and Constantinople. 551 In brickwork, there also seems to have been a tendency for the thickness of bricks to get less, and for the amount of mortar between them to increase.

The reuse of building materials is an intrinsic characteristic of early Byzantine church construction in west Asia Minor. The vast majority of dressed stone blocks in our churches seem to derive from earlier buildings. Reused carved elements were often incorporated in the structure without care to create a contrast between old and new architectural forms. Still, 552

The use of small amounts of iron and timber, in the form of cramps and ties, has been attested by cavities and cuttings in the structure. However, these elements now seem to have disappeared.

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188. Hierapolis, “Urban Basilica”, view of the south external wall. the rare cases in which spolia were displayed suggest that their use was not always purely utilitarian, but sometimes aimed to establish a symbolic association with the past. The impact of Spolia on construction should not be underestimated. At a time of decline in stone quarrying and trade networks, the reuse of locally available, and pre-carved stone elements must have been crucial in making vaulted construction in a monumental scale feasible.

reflect their important role of carrying the heavy loads and counteracting the lateral thrusts of major vaults (fig. 189). Pilasters project from the main body of piers, giving them a re-entrant angle profile. These projections must have facilitated the work of vault construction providing independent seating for the broad arches. The secondary load bearing system tends to match together heterogeneous elements. The marriage between walls and columns has been more challenging than it might seem (fig. 190). The survey of columns showed that their incorporation in the structure required the use of sophisticated techniques aiming to safeguard the brittle, monolithic marble shafts against various structural movements due to settlement or earthquakes.

Load Bearing Systems The various load bearing systems examined in chapter 2 seem to share a series of common constructional characteristics. The most important of these seems to be the division between a primary structure supporting the nave vaults, and a secondary structure, which either carries secondary vaults, or simply serves as a means of enclosure. The primary load bearing structure consisted of ashlar masonry piers, while the secondary one included marble colonnades and walls, whose structures often combines ashlar, brick and rubble masonry.

Masonry structures are characterized by the tendency for a liberal use of mortar. This leads to excessively thick mortar joints, which guarantee an even distribution of pressure between rough stones. Although the cohesion and stability of walls and supports owed a lot to the inherent strength of the mortar, they also relied on the disposition of the materials. Mortar seems to have been used to compensate for the mismatch between roughly shaped stones and to economise on brick but was not meant as a substitute for the overlap and bond between the materials.

The piers often consist of a relatively well-cut stone facing, and a core with rougher blocks, mixed with mortared rubble. Their large dimensions and strength

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Conclusions

189. Hierapolis, “Urban Basilica”, view of the remains of the main piers. Accustomed to the modern practice of constructing and replacing transient structures, it is difficult to understand the tendency of modifying earlier buildings and integrating their components in new structures. Load bearing systems in west Asia Minor were often amalgams between walls and supports of different periods. Indeed, the building of most of the vaulted churches examined involved the transformation of earlier basilicas. In many cases, earlier walls and supports were engulfed almost seamlessly in the load bearing structures, allowing builders to economise on materials and labour.553 In a few selected cases, however, the reasons for the blending of old and new structural components must have been wider, producing new architectural qualities and meanings.554

Vault Typology and Construction As the study of fragments gradually revealed the vault patterns employed in west Asia Minor, I started to realize that the current vault typologies were too restrictive to do justice to the variety and peculiarity of the emerging vault forms. The tendency to classify vaults solely according to their geometrical shape did not seem to be the best way to deal with vaults characterised less by their adherence to simple geometrical forms than by their particular brick layout. It soon became clear that the structure of vaults had to be reckoned with both in their description and in their classification. The use of the brick course layout as the principal criterion for classification led to the establishment of three main vault types. This typology does not simply constitute an academic tool used to organise the newly discovered forms; it reflects the way in which different vault forms were used and their structural roles. Vaults with radial brick courses, which constitute the first type,

553 According to A. Thiel (2005, table XVII), the construction of the vaulted transept and chancel of St. John at Ephesos seems to have retained extensive parts of the outer wall of the pre-Justinianic, timberroofed church. K. Tsakos (1979, p. 356) has shown that the construction of the vaulted basilica at Pythagorion incorporated parts of the harbour walls, as well as the surrounding walls of an earlier columnar Basilica. For the way in which the Caldarium of the Roman Baths of Hierapolis was turned into an aisled vaulted church, see M. L. De Bernardi, (2002, p. 273). 554 S. Karwiese (1999, p. 84) and H. Buchwald (1999, p. 13) show that the domed church of St. Mary only involved the reconstruction of the western part of the earlier, columnar basilica, leading in an interesting co-existence between a vaulted and a timber-roofed part. As S. Westphallen (2000, p. 275) has shown, at Priene, a series of fluted Doric

columns which had been reused as the main supports of an earlier columnar basilica, were retained in the screens between the piers of the vaulted basilica. In both these “hybrid” buildings, the co-existence of old and new, and the interface between them must have produced a unique architectural quality. For a survey of the symbolic potential of such buildings see R. Cormack (1990, p. 84).

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190. Ephesos, St. John, transept, view of the south aisle, illustrating the composite character of the load bearing system. The ashlar masonry pier on the left belongs to the primary system that carries the main spherical vaults, whereas the external brick walls and the colonnades play the secondary role of supporting the small aisle and gallery vaults.

either covered wide spans or were subjected to particularly heavy loads. Pitched brick vaults, on the other hand, were mostly used to cover small spans with a limited amount of centering. Vaults with arched brick courses, the third type, were used in exceptional cases. Provided that the craftsmen were capable of the virtuosity required in their construction, these vaults allowed limiting the use of centering, even when it came to the covering of significant spans.

of their emerging shape almost impossible without centering. It seems, therefore, that although certain vaulting techniques may have diminished the reliance on temporary formwork, they probably did not eliminate it altogether. Such techniques might have allowed replacing complicated and time-consuming types of centering with simpler devices, such as moveable templates. The use of such templates would have been inscribed in a “freehand” method of building, requiring exceptional building skills and relying considerably on the judgement of the builders.

The brick pattern of all the above vault structures seems to indicate the tendency to limit the use of timber formwork in their construction. Geometrically irregular vaults, such as the ones at Philadelphia and Ephesos, probably demonstrate that the control of the vault profile during construction was not very rigid. The regular use of techniques such as the setting of bricks at a “flat” inclination, or the division of the fabric into selfsupportive units have also been considered as indications of construction methods making limited use of centering. On the other hand, the flatness of some vault profiles meant that that at least some temporary support would have been essential for setting the bricks. Furthermore, the big size of some vaults would have made the control

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Appendix A Comparison between St. John at Philadelphia and Building D at Sardis.

The similarities between St. John at Philadelphia and Building D at Sardis found in the pier profiles, the absence of aisles, and the structural scale, have encouraged discussion concerning the possible existence of a local architectural tradition influencing both buildings.555 The latter have been seen as examples of an early Byzantine building typology characterised by a sequence of vaults supported by piers on a square or nearly square plan. Having examined the vault fragments at both Sardis and Philadelphia, it would be interesting to see whether the comparison between the vaulting techniques employed in the two cases confirms the alleged typological connection between them.

191. Philadelphia, St. John, northeast pier, cut away axonometric showing the springing of the pendentive. There is no intermediate structure between arch and pendentive (drawing by Nikolaos Karydis, 2009).

The overview of the remaining vault shells reveals a series of morphological and structural differences between the two buildings. Their pendentives must have been quite different, both in their connection with the supporting arches, and in geometrical form. On the one hand, at Sardis, there was an intermediate arched zone of radial bricks between the major arches and the pendentives, facilitating the connection between the two components (fig. 191). On the other hand, at Philadelphia, the pendentives seem to have lied directly on top of the extrados of the major arches (fig. 192). This must have resulted in a distortion of the pendentive shape, which did not necessarily occur at Sardis, where the border around the pendentives would have allowed giving the latter a spherical surface without irregularities (fig. 193). The difference in the bay proportions between the two monuments, often underestimated, is likely to have resulted in the adoption of different vaulting types. That would have made the spatial character of Building D significantly different from the one of St. John. Indeed, whereas at Sardis, the pendentives were parts of shallow pendentive domes, at Philadelphia, they probably 555 The investigation of the architectural vocabulary of this local tradition began by A. Choisy (1883, p. 160) who first examined the two buildings side by side. It continued through the articles of H. Buchwald (1984, p. 209). The latter has interpreted St. John at Philadelphia and Building D at Sardis, as belonging to a western Anatolian typology of buildings whose “spatial organization depends primarily upon a series of modular units”. Recent contributions to the same discussion include the one of A. M. Castelfranchi (1999, p. 97), who has emphasized the similarity of both monuments to St. John at Ephesos, which, according to her, may be indicative of a concerted building campaign aiming to honour St. John the Theologian, at each of the cities of the Apocalypse.

192. Sardis, Building D, southeast pier. Reconstructed axonometric showing the lower part of the pendentive, and the border separating it from the supporting arches (drawing by Nikolaos Karydis, 2009).

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Early Byzantine Vaulted Construction in the West Coastal Plains and River Valleys of Asia Minor supported full hemispherical domes (see figs. 186, 187). The vault cores of the two monuments are also different.556 Still, it is doubtful whether these constructional and morphological differences are enough to make us consider St. John at Philadelphia, and Building D at Sardis as products of two different building traditions. However dissimilar some of the vaulting components of the two buildings may be in structure and form, they nevertheless seem to express similar construction principles. Both the insertion of an arched border between arch and pendentive at Sardis, and the modification of the shape of the pendentives’ plan-curves at Philadelphia are simply different ways to avoid the same thing: the creation of a “weak” connection between pendentive and arch.557 Both techniques betray a common awareness of a generic problem of pendentive construction.558 In the construction of the vault cores of both buildings, the same precaution has been taken against the incoherence of the mortared rubble infill: in both cases this infill is interspersed with reinforcing bands (see figs. 123, 133). It is questionable whether a possible difference between the vaults of the two monuments indicates separate building practices. Indeed, both in Greece, and Constantinople, hemispherical domes on pendentives and pendentive domes were regularly used within the same context. Several examples attest this: St. Eirene at Constantinople and Basilica B at Philippi are instances where both vault types seem to have been used within the same building program.559 The replacement of the first, shallow dome of Hagia Sophia, after its collapse, by a hemispherical dome, provides further proof that both vault types were often considered to be interchangeable elements belonging to a common building practice.

193. Sardis, Building D, southeast pier, diagrammatic plan of the springing of the pendentive. A pendentive border (B), ensures the smooth transition between the shell of the pendentive (P) and the supporting arches (A) (sketch by Nikolaos Karydis, 2009). is concealed within the vaulted shell, at Sardis and Philadelphia, the entire structural mass of the arches can be easily distinguished from other elements.560 Each arch is completely independent from the surrounding arches,561 as well as from the pendentives that lie against it.562 Both pendentives and arches form an “additive” vault shell which seems, in its turn, to be completely independent from its backing, which is made of a different material. This tendency to give each vaulting component a distinctive form and structural independence made the connection between arches and pendentives difficult. The resolution of this issue at Sardis, through the insertion of a pendentive border, differed from the one at Philadelphia, which relied on the modification of the pendentives’ shape. This difference demonstrates the inventiveness of the local builders in dealing with problems resulting from common constructional and architectural choices.

In essence, the structures of Building D at Sardis and St. John at Philadelphia seem to share the same principles. In both cases, we encounter an interpretation of the main structural element of early Byzantine vaulting: the dome, either shallow or hemispherical, resting on pendentives. What characterises both these interpretations is the great independence, both morphological and structural, given to the constituents of this vaulting form: arches, pendentives / domes, and vault backing. Unlike early Byzantine structures where the greatest part of the arches 556 Even though the vault cores in both buildings consist essentially of mortared rubble, their reinforcing bands are completely different. At Building D, the builders seem to have privileged the use of solid brickwork in this element, quite unlike the builders of St. John who preferred to use a thick composite band of ashlar blocks and bricks for the same purpose. While at Sardis the faces of the reinforcing bands form part of the facing of the vault backing, at Philadelphia, these bands are concealed by a facing with its own, independent architectural articulation. 557 See A. Choisy (1883, pp. 90–94). 558 When the pendentives are perfectly spherical, their edges “strike” the extrados of the arches at an angle. This connection creates a weak area in the structure. 559 In the case of St. Eirene, in particular, this argument ought to be taken with a pinch of salt. Indeed, according to U. Peschlow (1977, p. 206), the western dome over the nave of St. Eirene resulted from an 8th century reconstruction. Yet, H. Buchwald (1984, p. 213) has expressed doubts about this chronology suggesting that the western dome was probably part of the original vault pattern.

560 H. Buchwald (1981, p. 316) states: “the structural mass of the arch is visible and it becomes an important aspect of the interior spatial articulation”. 561 This independence is underlined by the pier profiles, which allow each arch to be supported by an engaged pilaster. The corner merging between the arches, characteristic of buildings such as St. John at Ephesos, but also typical of St. Eirene and Hagia Sophia at Constantinople, does not occur at Sardis and Philadelphia. 562 At Sardis and Philadelphia, there are continuous joints, and a lack of bond between arches and pendentives.

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186

Constantinople, continued Church of the Holy Savior in Chora, 129(404) Hagia Sophia, 1, 29(62), 45(136), 48, 48(153), 62, 66(231), 67(232, 234), 72(248), 86–90, 98, 99(315), 101, 102, 104, 105, 113, 116, 121, 124(385, 386), 127, 129, 130(410), 131(416), 139(434), 143(439), 144(442), 157, 157(486), 158(500), 164(513), 169(531), 173, 182, 73, 104, 180 Myrelaion, 128(402), 171(535) St. Eirene, 1, 63(222), 67(232, 234), 72(248), 81(260), 88, 88(280), 90, 93, 98, 101, 104, 105, 111–113, 121, 124(385), 127, 128(402), 129, 131(411, 417, 418), 144(442), 169(531), 173, 182, 100–103, 106 Sts. Sergios and Bakchos, 67(234), 98, 99, 99(315), 105, 106, 130(410), 143(439), 111 Curtius, E., 17 Cyprus, 131(411)

Index

References to the footnotes are given to the page on which the footnote occurs, followed by the number of the footnote; thus, 86(274) indicates page 86, footnote 274. The names of modern scholars listed in the bibliography are indexed only if they are referred to in the main text. Numbers in bold italics refer to illustrations.

De Bernardi, M. L., 19 Deichmann, F. W., 6 Derea÷zƭ (Lycia), Church, 72(248) Docheiarion Monastery (Mount Athos), 66(231) Dura-Europos (Syria), 167

Aegean Coastlands, 24, 98, 169 Aegean Sea, 3, 34 Agathias, 86(274) Alahan Monastery (Cilicia), 34(90) Aliki (Thasos, marble quarries), 32, 50 Allom, Th., 16 Amphilochius (Bishop of Iconium), 32, 32(80) Anatolian Plateau, 3, 34 Andalusia, 85 Ankara, St. Clement, 151 Anthemios of Tralles (Mechanopoios, 6th Century), 98(310) Aphrodisias, 2 Cathedral, 165(516), 177 Armenia, 34 Asia (Province), 3 Aspendos, 154, 167 Basilica, 54(189), 167 Assur (Mesopotamia), 167(521) Athens, Archaeological Society, XV Athens, Ilissos Basilica, 131(416) Ayasoluk (see also Ephesos), 8, 55, 98

Egypt, 167 Elaeusa, Roman Imperial Baths, 49 Ephesos, 1, 2, 3(5, 8), 4, 43, 43(120), 44, 44(131) Celsus Library, 54(189) Harbour Baths, 32(79), 42(113), 115(363), 161 Mausoleum of Abradas, 131(412) Nymphaeum, 92 Olympieion, 42 St. John the Theologian, 3, 7, 8–13, 37(94), 55(186), 62(217), 69, 94(299), 98(312), 100(322), 100(323), 101–106, 174–176, 2, 7–9, 39, 112–114, 183–185 - Baptistery, 11, 13(37), 32(76), 46, 54, 71, 83, 98, 168, 169(530), 175, 7, 10, 96, 185 - Building materials employed, 27, 29–40, 32(84), 34(87), 39(102), 41(107), 42–49, 44(126), 46(144), 28, 30, 34, 37, 39, 41, 46, 48–50, 54 - Mosaic decoration, 76, 76(251), 86 - Skeuophylakion, 11, 27, 43(125), 46, 51, 51(175), 54, 71, 83, 11, 97 - Structure of load bearing elements, 51, 53(185), 53– 57, 58(201), 59(202), 59–65, 60(206, 210), 158, 58, 60, 61, 66, 68, 70–72, 74 - Vault structure, 69(238), 69–106, 88(279), 93(297), 104(333), 157(485), 158(494), 169, 169(532), 173, 175, 75–85, 87–98, 112–116, 182, 184 St. Mary, 3, 4–8, 37(94), 65, 135, 135(421), 137, 148(456), 150(458), 151, 152, 177, 1, 3, 4, 6, 143, 144 - Baptistery, 5, 8, 28, 32, 46, 46(143), 49, 53, 55, 60(210), 92, 92(286), 93, 135, 135(424), 137, 137(430), 142–147, 143(439), 147(450), 148, 148(456), 157(483), 158(496), 166, 168, 169, 171, 177(549), 5, 6, 36, 146, 161, 166 - Building materials employed, 27, 30, 30(73), 34, 37, 39, 40, 43, 45, 46, 47, 49, 55, 29, 32, 38, 42, 44, 45, 51, 56 - Structure of load bearing elements, 51, 53, 55, 56, 62, 157, 57, 62 - Vault structure, 135–154, 157(483), 166, 169–171, 177, 145, 147, 149–155, 162–166, 178, 181

Borra, G. B., 16 Bouras, Ch., XV Buchwald, H., XV, 4, 16, 17, 117 BüyükkolancÕ, M., XV, 11, 13, 100 Cahill, N., XV Cameron, A., XV Cappadocia, 32 Caria, 37(95) Cariþin Grad, 131(416) Carrara (marble quarries), 42(118) Castelfranchi, M. F., 6, 14, 17, 129 Cato, 50(161) Choisy, A., XV, XVII, 1, 4, 14, 17, 50, 51, 98, 107, 117, 153, 155 Constantine of Rhodes, 86 Constantinople, 1, 8, 20, 24, 30, 51(174), 55(190, 194), 67, 114–116, 115(363), 130(410), 135, 168, 177(550), 182 Ahmet Paúa Mescidi, 171(535) Church of the Holy Apostles, 85–88, 131(411, 413) 187

Ephesos, continued Temple of Artemis, 41(111) Theatre Gymnasium, 55(192) Vedius Gymnasium, 32(79)

Mesaritis, N., 86 Mesopotamia, 167 Miletus, 161 Baths of Faustina, 161, 171, 172 Morocco, 85 Mount Athos, 66(231) Myra, Church of St. Nicholas, 131(416), 151 Mystras, Church of Virgin Hodegetria, 129(404)

Fasolo, F., 5, 8, 135, 150, 152 Foss, C., 6, 14 Galesion (mountain), 50 Garnier, T., 13 Gennadios (Bishop of Hierapolis), 19 George, W. S., 88, 112 Gerasa (Syria), West Baths, 164 Gortyna (Crete, Greece), St. Titos, 131 Greece, 30, 161, 167, 182 Greek Institute of State Scholarships (I.K.Y.), XV

Naples, 49 National Technical University of Athens, XV Nea Anchialos (Greece), 44(131) Nicaea, Koimesis Church, 128(402), 150(458), 151 Nicomedia, Baths, 171(535) Nicopolis (Greece), Roman Baths, 161 Ostrogoths, 41(111), 42 Ousterhout, R., 29

(179)

Hermos River, 3, 53 Hierapolis (Capital of Phrygia), XVII, 1, 3, 34, 41, 43, 45, 46, 53, 61, 63, 177 Church of the Thermae, 18, 19, 59(202), 60(206, 210), 63(219), 169, 179(553), 21, 22 Early Byzantine kilns, 30 “Urban Basilica”, 18, 20, 28, 34, 41(109), 43, 45, 46, 60, 62, 65, 2, 19, 20, 64, 188, 189 Hörmann, H., 11, 13, 69, 81, 100–102, 104 Hosios Loukas (Phokis), 129(405) Hueber, F., 13, 100

Palladios (Bishop of Aspuna, 5th Century), 6(15) Pamphylia, 167 Paros, Hekatontapyliani, 98, 99, 106 Parvis, M., 6 Pergamon, 27, 51(174) Serapeum, 27(57), 54(189), 161 Temple of Asclepios Soter, 54(189) Perigueux, St. Front, 67(232) Peristerai Church (Greece), 131(413) Philadelphia (Alaúehir), 1, 16, 16(46), 2 St. John, 3, 4, 16–18, 176, 1, 15–18, 133, 139, 140 -Load bearing structure, 57, 60–62, 62(215), 65, 67, 138 -Materials used, 27, 28, 30, 32, 32(85), 34, 41, 43, 46, 17, 47, 133 -Vault structure, 117–133, 157(483), 158, 158(494–501), 161, 162(507), 163, 176, 176(546), 126–137, 140–143, 187, 191 Philippi (Macedonia, Greece), Basilica B, 32, 35, 88, 93– 98, 101, 131, 131(411, 417), 169(531), 177(550), 182, 107–109 Phrygia, 3, 19, 20, 177 Pliny, 50(161) Plommer, H., 11, 13 Pompeii, 50(166) Priene, Theatre Basilica, 3, 18, 20–21, 37(95), 51, 54, 65, 179(554), 23, 24, 59 Proconnesus (marble quarries), 32, 43, 43(124) Procopius of Caesarea, 85–88, 175 Pythagorion (Samos), Tria Dontia Basilica, 3, 18, 21–23, 65, 25–27, 43

Ibn Battuta, 13, 85, 106(338) Ionia, 37(95) Isidoros of Miletus (Mechanopoios, 6th Century), 98(310) Italy, 165 Iviron Monastery (Mount Athos), 50(165) Justin I, 11 Justinian I, 11, 44(129), 85, 86, 152, 175, 176 Karanis (Egypt), 153 Karwiese, S., 5, 6, 8 Karydis, A., XV Karydis, D., XV Kaystros River, 3 Kaystros Valley, 11 Keil, J., 5, 81, 100 Kiefer, K., XV Kiel, M., XV Knoll, F., 5, 8, 135, 138, 142–144, 150 Korykos, Roman Imperial Baths, 49 Krautheimer, R., 6

Qasr Ibn Wardan (Syria), 34(90), 131, 144(442), 169(531)

Lampakis, G., 16, 69(236) Lancaster, L., 158 Lechaion, Basilica of St. Leonidas, 45(136) Lepcis Magna, 45(136) Lydia, 3

Ramesseum (Thebes, Egypt), 167(520) Rautman, M., XV, 164(514) Ravenna (Italy) “Mausoleum of Gala Placidia”, 164(513), 165(516) 176 St. Vitale, 48, 49(156), 143(439) Rome, 30(75), 55(194), 163 Baths of Caracalla, 163(509), 174 St. Peter’s, 158(500)

Magnesia (on the Meander), 154 Malalas, 86(274) Meander River, 3, 53(179) Meriamlik, Domed Basilica, 131 Meriç, R., 17

Sangarius River, Bridge of Justinian, 86(272) Saqqara (Egypt), 167(520) 188

Sardis Expedition (Archaeological Exploration of Sardis), 111(344) Sardis, 1, 112, 2 Building A, 47(146) Building C, 61(212) Building D (also Church D), XVII, 3, 4, 13–15, 176, 181, 1, 12–14, 117–119, 125, 186 - Materials used, 27, 28, 41, 43, 46, 46(139) 47, 49, 33, 53, 55 - Pier structure, 57, 60(210), 61, 117–119, 192 - Vault structure, 107–116, 176, 181, 182, 119, 120– 122, 124, 125, 173, 186, 193 Church E, 129(404), 147(452) Gymnasium, 43, 63(222), 115(363), 161, 164, 169, 175 Synagogue, 37(97), 43 Temple of Artemis, Tomb II, 161 Side, 164 Building IV (also “Martyrium”), 131(411), 133 East Mausoleum, 88, 92, 93, 102, 147, 169(532), 171, 105 Soknopaiou Nesos (Egypt), 153 Sotiriou, G. A., 8, 11, 45, 100 Spalato (Split), Diocletian’s Mausoleum, 88, 92, 93, 93(289), 147, 171, 173 St. Gregory of Nyssa, 32 St. Nikon, 50 Strube, Ch., 13 Syria, 167(522) Theodora (Byzantine Empress, 6th Century), 11 Thessaloniki Hagia Sophia (also “St. Sophia”), 48, 151, 152 Palace of Galerius, 47(147) Rotunda (also “St. George”), 167, 169(531) St. Dimitrios, 92, 93 St. Mary of the Coppersmiths, 128(402), 129(404) Thiel, A., 11, 13, 69, 100, 101, 173, 175, Tiberius (Roman Emperor), 45(137) Tornikes, G. (Metropolitan of Ephesos, 12th century), 85, 101 Touliatos, P., XV Tsakos, K., 21, 179(553) Turkey, XV Vasilikou, K., XV Venice, St. Mark, 67(232), 127, 131(413) Verzirken (quarries), 45 Verzone, P., 6, 19, 100, 173 Vitruvius, 50(161) Ward-Perkins, J. B., 35, 153, 155 Westphalen, S., 21 Wilson Jones, M., XV Wright, G. R. H., 51

189