Amphictyon was king of Thermopylae and married a daughter of Cranaus of Athens. He then deposed Cranaus, proclaiming himself king of Athens. He ruled Athens for ten years and founded the Amphictyonic League, which traditionally met at Thermopylae in historical times.
Amphictyon was deposed by Erichthonius, another autochthonous king of Athens.
Amphictyon won the kingdom thus. It is said that Actaeus was the first king of what is now Attica. When he died, Cecrops, the son-in-law of Actaeus, received the kingdom, and there were born to him daughters, Herse, Aglaurus and Pandrosus, and a son Erysichthon. This son did not become king of the Athenians, but happened to die while his father lived, and the kingdom of Cecrops fell to Cranaus, the most powerful of the Athenians. They say that Cranaus had daughters, and among them Atthis; and from her they call the country Attica, which before was named Actaea. And Amphictyon, rising up against Cranaus, although he had his daughter to wife, deposed him from power. Afterwards he himself was banished by Erichthonius and his fellow rebels. Men say that Erichthonius had no human father, but that his parents were Hephaestus and Earth.