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.
Kingdom of Chalcis
Originally, Chalcis was a city in Coele-Syria. When the Seleucid influence in the area began to dissipate, the Itureans created the Kingdom of Chalcis, which stretched from the Mediterranean Sea to near Damascus. They made Chalcis the capital of their realm, Baalbek was the center of worship. The founder of the kingdom seems to have been Ptolemaeus, son of Menneus, an Ituraean dynast.