Gambrion is first mentioned in Xenophon’s Hellenika as being ruled by Gorgion, son of Gongylos. He provided some support, along with Prokles of Teuthrania, to Xenophon in escaping from a botched kidnapping attempt.
The city was named after a son of Hermes who threw himself into a river (later named for him) after sleeping with his sister. The city was very close to Pergamon.