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.
Nicene Christianity
Chalcedonian Christianity is a large subset of Nicene Christianity. In addition to subscribing to the Nicene Creed, Chalcedonian Christians also subscribe to the decisions of the First Council of Ephesus in AD 431 and of the Council of Chalcedon in AD 451. The great majority of Nicene Christians are also Chalcedonian Christians. However, some portions of Eastern Christianity such as the Oriental Orthodox Churches and historically Church of the East adhere to the Nicene Creed but not to the Chalcedonian Definition and are therefore part of Nicene Christianity but non-Chalcedonian and for latter "non-Ephesine".