Interior of Hagia Sophia, Istanbul (formerly Constantinople)

During the late middle ages Constantinople remained the see of the Ecumenical Patriarch, the chief bishop of the eastern churches. During the Fourth Crusade, initially directed against Saladin in Egypt, crusaders were dispatched to attack Constantinople and claim it for the West. The Latin empire of Constantinople was established there from 1204-1261. Byzantine Christians reconquered the city in 1261. The episode deepened the division between the eastern and western churches. Throughout the early middle ages Constantinople eclipsed Rome as a political center and capital of the empire. Throughout the early middle ages estrangement increased between the ecumenical patriarchs in Constantinople and the popes in Rome. Constantinople became the primary center for what would later formally emerge as the Orthodox churches of the East.