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.
New Rome
New Rome (Greek: Νέα Ῥώμη, "Nea Romē"; Latin: "Nova Roma") was a name sometimes used to describe the new city that the Roman Emperor Constantine created as his new imperial capital on the European coast of the Bosphorus strait. The city was known as Byzantium prior to his rededication, and as Constantinople thereafter, until the 20th century, when it was renamed Istanbul. 'New Rome' was never an official title, but was sometimes used as a laudatory description of the city, which was often compared with Rome in many ways.