Chalcedon

Chalcedon is an ancient Greek polis located on a peninsula along the eastern shore of the Bosporus, within what is now the Kadıköy district of Istanbul. The settlement stretched along the waterfront opposite the European side, where residential neighborhoods and modern roads have largely covered the original layout.

Colonists from Megara founded the settlement in 685 BCE, creating one of the early Greek colonies along the strait. Persians conquered the city in the 6th century BCE, and it later became part of the Roman Empire before being fully absorbed into the growing Constantinople during the medieval period.

The Fourth Ecumenical Council of 451 CE convened in Chalcedon to establish fundamental Christian doctrinal principles regarding Christ's divine nature.

Visitors reach the ancient site area by ferry or public transport from the European side of Istanbul, though above-ground remains are sparse. The best points of reference lie near the Kadıköy waterfront district, where occasional archaeological fragments are embedded into modern streets.

The city gives its name to the mineral chalcedony, which was quarried from the surrounding area in ancient times. This material was later used in large quantities for building structures and fortifications in neighboring Constantinople.

Location: Kadıköy

Inception: 680 BCE

GPS coordinates: 40.98333,29.03333

Latest update: December 14, 2025 17:24