Chalcedon
The site of Chalcedon is located on a small peninsula on the north coast of the Sea of Marmara, near the mouth of the Bosphorus. A stream, called the Chalcis or Chalcedon in antiquity and now known as the Kurbağalıdere (Turkish: "stream with frogs"), flows into Fenerbahçe bay. There Greek colonists from Megara in Attica founded the settlement of Chalcedon in 685 BC, some seventeen years before Byzantium.
Exarch
The Council of Chalcedon (451), which gave special authority to the see of Constantinople as being "the residence of the emperor and the Senate," in its canons spoke of diocesan "exarchs", placing all metropolitans in dioceses of Asia, Thrace an Pontus (including metropolitans-exarchs of Ephesus, Heraclea and Caesarea) under the jurisdiction of the Archbishop of Constantinople. Metropolitans-exarchs of Ephesus tried to resist the supreme jurisdiction of Constantinople, but eventually failed since imperial government supported the creation of a centralized Patriarchate.