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
Already by the early 5th century however, Constantinople had expanded outside the Constantinian Wall, in the extramural area known as the "Exokionion" or "Exakionion". The wall survived during much of the Byzantine period, even though it was replaced by the Theodosian Walls as the city's primary defence. An ambiguous passage refers to extensive damage to the city's "inner wall" from an earthquake on 25 September 478, which likely refers to the Constantinian wall, and Theophanes the Confessor reports renewed earthquake damage in 557. It appears that large parts survived relatively intact until the 9th century: the 11th-century historian Kedrenos records that the "wall at Exokionion", likely a portion of the Constantinian wall, collapsed in an earthquake in 867. Only traces of the wall appear to have survived in later ages, although Van Millingen states that some parts survived in the region of the "İsakapı" until the early 19th century. The recent construction of Yenikapı Transfer Center has unearthed a section of the foundation of the wall of Constantine.