Christianity in Turkey
Constantinople became established in the ecclesiastical hierarchy at the Council of Constantinople in 381. Second only to Rome, the legendary origins of the Patriarchate of Constantinople go back to St. Andrew, Metrophanes and Alexander of Constantinople. Constantinople's primacy over the Patriarchates of Alexandria and Antioch was reaffirmed at the Council of Chalcedon in 481, after which the papacy in Rome supported Constantinople in its dispute with Alexandria over monophysitism. Later, when Rome sought to assert its primacy over Byzantium, the Eastern Orthodox church developed the doctrine of pentarchy as a response.
Walls of Constantinople
Like Severus before him, Constantine began to punish the city for siding with his defeated rival, but soon he too realized the advantages of Byzantium's location. During 324–336 the city was thoroughly rebuilt and inaugurated on 11 May 330 under the name of "Second Rome". The name that eventually prevailed in common usage however was Constantinople, the "City of Constantine" (Gk. Κωνσταντινούπολις, "Konstantinoupolis"). The city of Constantine was protected by a new wall about 2.8 km (15 "stadia") west of the Severan wall. Constantine's fortification consisted of a single wall, reinforced with towers at regular distances, which began to be constructed in 324 and was completed under his son Constantius II (r. 337–361). Only the approximate course of the wall is known: it began at the Church of St. Anthony at the Golden Horn, near the modern Atatürk Bridge, ran southwest and then southwards, passed east of the great open cisterns of Mocius and of Aspar, and ended near the Church of the Theotokos of the Rhabdos on the Propontis coast, somewhere between the later sea gates of St. Aemilianus and Psamathos.