Chalcedon
Chalcedon ( or ;
, sometimes transliterated as "Chalkedon") was an ancient maritime town of Bithynia, in Asia Minor. It was located almost directly opposite Byzantium, south of Scutari (modern Üsküdar) and it is now a district of the city of Istanbul named Kadıköy. The name "Chalcedon" is a variant of Calchedon, found on all the coins of the town as well as in manuscripts of Herodotus's "Histories", Xenophon's "Hellenica", Arrian's "Anabasis", and other works. Except for a tower, almost no above-ground vestiges of the ancient city survive in Kadıköy today; artifacts uncovered at Altıyol and other excavation sites are on display at the Istanbul Archaeological Museum.
Chalcedonian Christianity
The dogmatical disputes raised during the Council of Chalcedon led to the Chalcedonian Schism thus to the formation of the Non-Chalcedonian body of churches known as Oriental Orthodoxy. The Chalcedonian churches remained united with the Holy See of Rome, the Ecumenical Patriarchate of Constantinople (or "New Rome") and the Eastern Orthodox patriarchates of the Middle East (namely Alexandria, Antioch and Jerusalem). Together, these five patriarchates were considered the pillars of orthodox catholic Christendom and of the Chalcedonian confession of faith. During the 6th-century reign of Emperor Justinian I, the five patriarchates were recognised as the Pentarchy, the official ecclesiastical authority of the Imperial Christian Church.