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.
Ancient Rome
He was defeated by the Franks and the Alamanni during 306–308. In 324 he defeated another tetrarch, Licinius, and controlled all the empire, as it was before Diocletian. To celebrate his victories and Christianity's relevance, he rebuilt Byzantium and renamed it Nova Roma ("New Rome"); but the city soon gained the informal name of Constantinople ("City of Constantine"). The reign of Julian, who under the influence of his adviser Mardonius attempted to restore Classical Roman and Hellenistic religion, only briefly interrupted the succession of Christian emperors. Constantinople served as a new capital for the Empire. In fact, Rome had lost its central importance since the Crisis of the Third Century—Mediolanum was the western capital from 286 to 330, until the reign of Honorius, when Ravenna was made capital, in the 5th century.