History of the Peloponnesian War

It is reported that Apollo by his oracle did assign this place for an habitation to Alcmaeon the son of Amphiareus, at such time as he wandered up and down for the killing of his mother, telling him that he should never be free from the terrors that haunted him till he had found out and seated himself in such a land as when he slew his mother, the sun had never seen nor was then land because all other lands were polluted by him. Hereupon being at a nonplus, as they say, with much ado he observed this ground congested by the river Achelöus and thought there was enough cast up to serve his turn already since the time of the slaughter of his mother, after which it was now a long time that he had been a wanderer.

Therefore, seating himself in the places about the Oeniades, he reigned there and named the country after the name of his son Acarnas. Thus goes the report, as we have heard it concerning Alcmaeon.