1 Fleming, J., Honour, H., Pevsner, N., The Penguin Dictionary of Architecture (London, 1980), p. 17 Google Scholar.

2 Al-Janabi, Tariq Jawad, Studies in Medieval Iraqi Architecture (Baghdad, 1982), p. 231 Google Scholar. An example of this form is found in the zone of transition of the muqamas dome of the Turba of al-Shaikh ‘Umar al-Suhrawardi in Baghdad, datable before 1225 as illustrated by Al-Janabi in Plate 91. The tomb chamber, almost square in plan, has an interior zone of transition consisting of three layers, which ultimately convert the square shape of a chamber to a sixteen-pointed star. This zone of transition is vital to our understanding of the relationship between the shouldered arch and the tri-lobed arch. The transitional element here can be read as either of these arch forms. If the window is ignored, the arch profile is that of a shouldered arch; however, if the window is read as part of the profile, it becomes the upper lobe of a tri-lobed arch.

3 Ibid., p. 231.

4 Papadopoulo, Alexandre, Islam and Muslim Art (London, 1980)Google Scholar, trans. Robert Erich Wolf, p. 267.

5 Hillenbrand, Robert, Islamic architecture (Edinburgh, 1994), pp. 289-91Google Scholar, pl. 201.

6 Fletcher, Banister, A History of Architecture on the Comparative Method, 14th edn (London, 1948), p. 64 Google Scholar.

7 Gye, D. H., ‘Arches and Domes in Iranian Islamic Buildings: An Engineer’s Perspective’, Iran, XXVI (1988), pp. 129-44CrossRefGoogle Scholar (p. 138).

8 Ibid., pl. 111a.

9 See the shouldered-arch vaulting of the gallery at the top of the staircase salient of the gateway of Bab al-Nasr (c. 1087) in Creswell, K. A. C., The Muslim Architecture of Egypt, 2 vols (Oxford, 1952), 1 Google Scholar, pl. 56a. Other examples are found in the tomb tower of Bastam and the Sah Gunbad at Uimiya/Rida’iya. See Hillenbrand, Robert, ‘The Flanged tomb tower at Bastam’, Art et Société dans le Monde Iranian, ed. Adle, C. (Paris, 1982), pp. 252-54Google Scholar.

10 Examples of the pendentive in Roman and Byzantine architecture include St Saviour in Chora and Medresesi Karatay, Konya. See Mainstone, Rowland J., ‘Squinches and Pendentives: Comments on Problems of Definitions’, Art & Archaeology Research Papers, 4, (1973), pp. 13–37 (p. 135)Google Scholar.

11 Ibid., p. 135. See also Creswell, K. A. C., ‘The squinch before A.D. 700’, Early Muslim Architecture, 2 vols, 2 (New York, 1979), pp. 101-18Google Scholar (pp. 101-02, figs 85, 91 & 92).

12 An early and undeveloped use of the squinch zone solution is found in the main dome chamber of the Palace at Sarvistan. See Pope, Arthur Upham and Ackerman, Phyllis, A Survey of Persian Art, 16 vols (Ashiya, 1977), 2 Google Scholar, Plate 148c and K. A. C. Creswell, ‘The squinch…’, Early Muslim Architecture, 2 (figs 90 & 93).

13 See Pope, A Survey of…, Vol. 8, plate 264A.

14 Ibid., Vol. 8, plate 320.

15 Smith, Myron Bement, ‘Material fora Corpus of Early Iranian Islamic Architecture: II. Manar and Masdjid, Barsian (Isfahan)’, Ars Islamica, IV (1937), pp. 7–41 Google Scholar (figs 4, 5 & 12) and Pope, Survey, Vol. 8, plate 230.

16 See Pope, , Survey, Vol. 3, pp. 1001-02Google Scholar and Vol. 8, plate 274a. See also Hillenbrand, Robert, ‘The Development of Saljuq Mausolea in Iran’, The Art of Iran and Anatolia from 11th to 13th centuries, AD (London, 1974), p. 53 Google Scholar. The Duvazdah Imam in Yazd is important in that it contains the rudimentary elements that were to become characteristic of Saljuq architecture as a whole. It is here that we first experience the Saljuq taste for verticality manifested and achieved through the grandiose squinch arrangement.

17 Gye, , ‘Arches and Domes…’, Iran, XXVI, pp. 129-44Google Scholar (pp. 132–36). And see Heyman, J., The Stone Skeleton (Cambridge, 1995), pp. 18fCrossRefGoogle Scholar.

18 See Hillenbrand, Islamic Architecture, pp. 290–91.

19 The earliest examples occur at the Masjid-i Jami in Isfahan in both the south (c. 1080) and north (c. 1088) dome chambers where the shouldered-arch profile appears in the form of a blind niche either flanking or enclosing blind pointed arches respectively.

20 For an example see Hillenbrand, Islamic architecture, p. 36, Fig. 2.226.

21 Hillenbrand, Islamic architecture, pp. 289-91, plate 201.

22 Pope, , Survey, Vol. 3, p. 987 Google Scholar and Vol. 8, plate 268a.

23 Pope, , Survey, Vol. 3, p. 1002 Google Scholar and Vol. 8, plate 274a & c.

24 See Schroeder, Eric, ‘The Seljuq Period’, Pope, , Survey, Vol. 3. pp. 1009–14Google Scholar. As Schroeder points out these monuments are characterized by the tri-lobed squinch type and a concentration on architectural form. Hillenbrand also cites this distinguishing feature of the ‘Isfahan school’ in Hillenbrand, Robert, ‘Saljuq Dome Chambers in North-West Iran’, Iran, 14 (1976), pp. 93–102 CrossRefGoogle Scholar, (p. 97). It becomes a leitmotiv and has become a source of decorative as well as structural strength in the monuments of this region yet it remains noticeably absent from Saljuq architecture of north-west Iran.

25 Pope, , Survey, Vol. 3, pp. 1005-15Google Scholar.

26 Hillenbrand, , ‘Saljuq Dome Chambers…’, Iran, 14, pp. 93–102 CrossRefGoogle Scholar.

27 Ibid., p. 97.

28 Hillenbrand, Islamic Architecture, p. 343.

29 Ibid., pp. 343-44.

30 Loc. cit.

31 See Godard, André, ‘Khorasan’, Athar-e Iran, (Haarlem, 1949) pp. 7–150 Google Scholar (Fig. 44).

32 Hillenbrand, ‘Saljuq Dome Chambers…’, Iran, p. 102.

33 Godard, ‘Khorasan’, Athar-e Iran, p. 37, Fig. 29.

34 See Al-Janabi, Studies in Medieval…, and Schmidt, J., Die Madrasa al-Mustansiriya in Baghdad (Mainz, 1984), pl. 22 Google Scholar.

35 Gye, , ‘Arches & Domes…’, Iran, XXVI, p. 144 Google Scholar. In his footnote No. 25 he points out the analogy between muqamas vaulting and hammerbeam vaulting. Whether the techniques arose for similar structural reasons is not clear but one cannot fail to note the visual similarity of effect.

36 Al-Janabi, Studies in Medieval…, p. 233.

37 See Tabbaa, Yasser, ‘The Muqarnas Dome: Its Origin and Meaning’, Muqarnas, 3 (1985), pp. 65–66 Google Scholar.

38 See Strzgowski, J. & van Bercham, Max, Amida (Heidelberg, 1910)Google Scholar, plates IX, X and XL.

39 This tendency also appears in the doorway entrance to the staircase of the northern minaret in the mosque of al-Hakim in Cairo (completed 1002) which was attributed by Creswell to a different architect from the rest of the complex. A craftsman from abroad, Anatolia perhaps? See Creswell, , The Muslim Architecture of Egypt, 1, p. 91 Google Scholar, Fig. 33. ‘[It] is set in a shallow recess and its lintel rests on a pair of pilasters with splay face capitals which give quite a Doric appearance.’

40 Aslanapa, Oktay, Turkish Art & Architecture (London, 1971), p. 94 Google Scholar. See also Unsal, B., Turkish Islamic Architecture in Seljuk and Ottoman Times 1071-1923 (London, 1959), p. 84 Google Scholar, fig. 45 for an example of the shouldered arch first used in Bursa in the Green and Beyazit 1 Mosques and described by him as ‘flat in the middle with a quarter circle at each side’.

41 See Aslanapa, Turkish Art…, p. 93.

42 Ibid., p. 128, Fig. 64.

43 Brend, Barbara, ‘The patronage of Fahr ad-din Ali Ibn al-Husain and the work of Kalik ibn Abd Allah in the development of the decoration of portals in 13th century Anatolia’, Kunst des Orients, 1-2 (1975), pp. 160-86Google Scholar.

44 See Janine Sourdel-Thomine, Die Kunst des Islam, pl. 249 — where the lowest tier of stalactite niches are in the form of shouldered arches as first seen in the squinch zones of Saljuq mosques in Iran. For further discussion of the Gok Medrese at Sivas, see Rogers, J. M., ‘The Cifte Minare Medrese at Erzurum and the Gok Medrese at Sivas’, Anatolian Studies, 15 (1965), pp. 63–84 CrossRefGoogle Scholar.

45 See Hoag, John D., Islamic Architecture (New York, 1977)Google Scholar. See plate 181 for detail of the muqarnas and plate 182 for a general view of the façade.

46 See Briggs, Malcolm S., Muhammadan Architecture in Egypt and Palestine (Oxford, 1924), p. 128 Google Scholar.

47 Aslanapa, Turkish Art…, p. 96.

48 Ibid., fig. 17.

49 See the scene ‘A Royal Polo Game’ from a Persian Safavid miniature (1501-1732) from the Samuel S. White, 3rd & Vera White Collection in the Philadelphia Museum of Art. This scene from the Shahnameh shows the Persian Crown Prince, Siyavish and his team play the Royal team of Turkestan. The King of Turkestan, Afrasiyab watches the game from an elevated position surrounded by a concave shouldered-arch frame. It is also no coincidence that during the Saljuq period there is a predominant use of the tri-lobed arch as a framing device for Royal enthronement scenes; see for example ‘Bahram Chubina Enthroned’, a leaf from a dispersed copy of a Shahnameh, Shiraz, 1341 in The Katherine Kittredge McMillan Memorial Fund (51.37.23) in Sims, Eleanor G., ‘Persian Miniature Painting in The Minneapolis Institute of Arts’, The Minneapolis Institute of Arts Bulletin, Vol. 62 (1975), pp. 51–73 Google Scholar, Fig. 2. The tri-lobed profile works architecturally here, in much the same way that it is used in buildings, articulating the axis and focus of the scene, whilst on another level suggesting a religious association with its predominant use in mosque architecture. Indeed, such is the symbolism of the tri-lobed arch in Saljuq and Mongol Iran that in miniature painting even the ruler’s crown was depicted in the shape of the tri-lobed/trefoil arch and is known today as the ‘Saljuq crown’. For examples of the tri-lobed arch used as gravestones, see also G. C. Miles, ‘Epitaphs from Isfahan Graveyards’, Ars Islamica, (1939), p. 151.

50 Ibrahim, Laila Ali, ‘The Transitional Zones of Domes in Cairene Architecture’, Kunst des Orients, 10 (1975), pp. 5–23 Google Scholar (p. 6).

51 It is first found in abundance in the sahn of the Mosque of al-Azhar founded c. 972. See Creswell, , Muslim Architecture of Egypt, Vol. 1, pls 89 Google Scholar & 90. Similar suggestions have been made in relation to English fan vaulting where each element has the same curvature as its neighbours and’thus lends itself to more rapid and simpler production techniques.

52 Ibid., Vol. 1, Plates 78 and 110d & e.

53 Creswell, Muslim Architecture of Egypt, Vol. 1. Examples include the Mausoleum of Sayyida ‘Atika, plates 80, 81 & 110d; the Mausoleum of Ikhwat Yusuf (1100-25), p. 235, plate 112 e & f which shows both the keel and characteristic tri-lobed/shouldered arch being used as balancing and articulating devices in the zone of transition. Similarly in the Mausoleum at Qus (1120-30), p. 223, plate 85b, c & d the tri-lobed/shouldered arch is used to create balance and symmetry throughout the building whilst also emphasizing axiality.

54 Smith, ‘Material for a Corpus … Barsian’, Ars Islamica, p. 22.

55 Wilber, Donald, The Architecture of Islamic Iran: The Il-Khanid Period (New York, 1969), p. 128 Google Scholar.

56 Seherr-Thoss, Sonia P., Design and Colour in Islamic Architecture (Washington, 1968)Google Scholar, plate 44.

57 See Hoag, Islamic Architecture, Fig. 33B and Pope, Survey, Vol. 8, Plate 407.

58 Al-Janabi, Studies in Medieval…, p. 110, plate 91.

59 Ibid., pp. 91-95, plates 63 & 64.

60 Wilber, The Architecture of…, pp. 121-23 and Pope, Survey, Vol. 8, plate 386a.

61 Ibid., p. 33 and Pope, Survey, Vol. 8, plate 367.

62 Wilber, The Architecture of…, p. 139 & Seherr-Thoss, Design and Colour…, plate 38.

63 Hillenbrand, ‘The Flanged Tomb…’, p. 237.

64 Hillenbrand, Robert, ‘Saljuq Monuments in Iran II, The “Pir” Mausoleum in Takistan’, Iran, x (1972), pp. 45–55 CrossRefGoogle Scholar (p. 48, pls 111a & b).

65 See Rogers, , ‘The Cifte Minare Medresè at Erzurum…’, Anatolian Studies, 15, pp. 63–84 CrossRefGoogle Scholar.

66 Wilber, The Architecture of…, p. 160. The caravanserai at Sarcham shows a rare example of this use, with the appearance of a shouldered-arch window that sits centrally above the portal entrance. See Godard, André, ‘Notes Complémentaires sur les Tombeaux de Maragha’, Athar-e Iran, 1 (1936), p. 148 Google Scholar, figs 104 & 105.

67 Aslanapa, Turkish Art…, plates 37 & 38.

68 Wilber, The Architecture of…, fig. 55.

69 See Blair, Sheila S. and Bloom, Jonathan, The Art and Architecture of Islam 1250-1800 (New Haven, 1994)Google Scholar, Fig. 119.

70 Hoag, Islamic Architecture, plates 181 & 182.

71 Blair and Bloom, The Art and Architecture…, fig. 118 — the complex of Qayt Bay in Cairo (1472-74).

72 Laila Ali Ibrahim, ‘The Transitional Zones …’, Kunst des Orients, 10. Examples include the Mausoleum of Sagar al-Durr (fig. 5) and the Mausoleum of Ganibak al-Asrafi (fig. 17).

73 Briggs, Muhammadan…, p. 128.

74 See Creswell, Muslim Architecture…, Vol. 2. Examples include Bayt al-Qadi or the muq’ad of the palace of the Amir Mamay (1495).