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.
Nicaea
After the fall of Constantinople to the Fourth Crusade in 1204, and the establishment of the Latin Empire, Nicaea escaped Latin occupation and maintained an autonomous stance. From 1206 on, it became the base of Theodore Laskaris, who in 1208 was crowned emperor there and founded the Empire of Nicaea. The Patriarchate of Constantinople, exiled from Constantinople, also took up residence in the city until the recapture of Constantinople in 1261. Although Nicaea was soon abandoned as the primary residence of the Nicaean emperors, who favoured Nymphaion and Magnesia on the Maeander, the period was a lively one in the city's history, with "frequent synods, embassies, and imperial weddings and funerals", while the influx of scholars from other parts of the Greek world made it a centre of learning as well.