Adrastus, a legendary king of Argos, in the history of ancient Greece. His father was Talaus, king of Argos. Being expelled from Argos, he took refuge in Sieyon, and there succeeded to the throne, and instituted the Nemean games. He was subsequently restored to his native city, and married one of his daughters to Polynices, son of (Œdipus and brother of Eteocles, who had been deprived by the latter of his share in the reign over Thebes. He now formed a union of Greek heroes to restore his son-in-law to his throne, and led the famed expedition of the "seven against Thebes," the abundant theme of later tragedy. Adrastus alone survived, saved by the fleetness of his horse Arion. Ten years later he prompted the seven sons of the defeated heroes to renew the war. Their expedition, known as that of the epigoni or descendants, set out with promises of success from the oracle, and ended with the capture and complete demolition of Thebes. The son of Adrastus was the only Argive that fell, and Adrastus himself soon after died of grief.