Chalcedon was an ancient city located in what is now modern-day Turkey, near the Bosporus Strait. It was founded by Greek colonists from Megara around 685 BC and became an important trade center due to its strategic location. Chalcedon is known for its rich history and was part of various empires, including the Roman and Byzantine Empires. The city is most famous for the Council of Chalcedon, which took place in 451 AD. This ecumenical council addressed key theological disputes within early Christianity, particularly concerning the nature of Christ. The decisions made at this council significantly influenced Christian doctrine and the development of the Eastern Orthodox and Catholic Churches.