The town was founded as a colony of the Colophonians and was called Μύρλεια (Myrleia or Myrlea). Philip V of Macedon took the town, as it appears, during his war against the king of Pergamon, and gave it to his ally, King Prusias I of Bithynia, who fortified and enlarged it – indeed almost rebuilt it – around 202 BC, renaming it Ἀπάμεια (transcribed as Apameia, Apamea, or Apamia), after his wife, Apama III.
The place was on the west coast of the Gulf of Gemlik, and northwest of Bursa, then called Prusa, for which it served as a port.
The Romans made Apamea a colonia, apparently in the time of Augustus, or perhaps Julius Caesar, in view of the adjective "Iulia" that appear on its coins under Roman rule. Its earlier coins were stamped Ἀπαμέων Μυρλεάνων, but in Roman times they bore the label C.I.C.A. (Colonia Iulia Concordia Apamea).
When Pliny the Younger was governor of Bithynia, he consulted Trajan about a claim by the colonia not to have its accounts of receipts and expenditures examined by the Roman governor.
A passage of Ulpian shows use of the adjectival form of the name was Apamenus: "Apamena: est in Bithynia colonia Apamena.