in the mosque of Ziadat Allah in Kairawan (A.H. 816-837); “nor does it seem an unnatural conjecture that it was Jauhar, not only a distinguished general, but also a man of letters, and therefore of culture, who suggested the form to some Christian architect of Egypt: and that, under these circumstances, the designer of the building, wishing to endow it with some distinctive feature marking the accession of the new dynasty, modified the pointed arch of Tulun’s time under the influence of the Indian ‘cyma reversa’ or ogee arch” (Rivoira: op. cit. 157). In general plan, style, the use of brick piers, etc., the mosque of al-ʾAzhar followed the model of the mosque of Ibn Tulun, and so was a development of Egyptian native taste. The minaret was of heavy square type with outside stairs which has always remained popular in western Islam. The most novel feature introduced by the Fatimid architects was the pendentive, the pensile cusped framing arch over a recessed angle. This appears clearly in the interior of the dome of the mihrab in the mosque of al-Hakim, commenced in 380 but not completed until 404. But this reproduces the pendentive as it appears in the mosque of Cordova (A.H. 350-366) in the bay in the front of the mihrab, and had its precursor more than four centuries before in the church of St. Vitale at Ravenna. It is impossible, therefore, to connect Fatimid architecture with Persia: obviously it was developed out of the older Egyptian Muslim style under the influence of western and European, _i.e._, Italo-Greek, models. As usual, art is a clear indication of the general line of culture contact and intellectual influences. Though Asiatic and Persian in origin the Fatimids were, by their heretical character, entirely cut off from the Islamic world in Asia, a severance which the Fatimid rule in Syria, being one of purely military occupation, did not bridge over. Isolated in art, it was isolated in philosophy and literature, although this isolation from the Muslim world at large was richly compensated by its close contact with Shiʿite circles, and by some contact with the Greek and Roman Empire along the shores of the Mediterranean. The wall surrounding the whole city of Kahira was finished in 359. To its south-east lay the old city which remained the centre of commercial and non-official life until the end of the Fatimid dynasty, and to the west the suburbs of Maqs, which extended down to the river and remained the port of Cairo until the shifting of the Nile in the 13-14th cent. A.D. gave the opportunity for the building of Bulaq.