Having been driven from Argos by Amphiaraus, Adrastus fled to Sicyon, where he became king on the death of Polybus.
Adrastus, followed by Polyneices and Tydeus, his two sons-inlaw, Amphiaraus, his brother-in-law, Capaneus, Hippomedon and Parthenopaeus, marched against the city of Thebes, and on his way is said to have founded the Nemean games.
Ten years later, at the instigation of Adrastus, the war was renewed by the sons of the chiefs who had fallen.
None of the followers of Adrastus perished except his son Aegialeus, and this affected him so greatly that he died of grief at Megara, as he was leading back his victorious army.
He took part in the voyage of the Argonauts and in the chase of the Calydonian boar; but his chief fame is in connexion with the expedition of the Seven against Thebes, organized by Adrastus, the brother of his wife Eriphyle, for the purpose of restoring Polyneices to the throne.