Constantinople

Constantinople, on the Bosporus between Europe and Asia, was refounded by Constantine in 330 on Byzantium and became the Byzantine capital. Its greatest shrine was Hagia Sophia.

A first Great Church was consecrated in 360, and after it burned the domed basilica was built under Justinian I between 532 and 537 as the patriarch's seat. In 1054 the papal envoy delivered there the excommunication that opened the East-West Schism, and from 1204 to 1261 Catholic clergy served the cathedral under the Latin Empire.

Paulician communities broken by imperial warfare were resettled in Thrace from the late ninth century, and in 970 John I Tzimiskes moved some two hundred thousand of them to the region of Philippopolis, where their dualist teaching helped feed the later Bogomil movement. When Ottoman troops stormed the city in 1453, Hagia Sophia was converted into a mosque.