|Form: Gr. Alkmaion,
|of Argos. Son of Amphiaraus (q.v.) and Eriphyle. As his father, in departing on the expedition of the Seven against Thebes, has bound him and his brother Amphilochus, then mere boys, to avenge him on their faithless mother, Alcmaeon refuses to take part in the second expedition, that of the Epigoni (q.v.), till he has first fulfilled that filial duty; nevertheless his mother, bribed by Thersander with the garment of Harmonia, persuades him to go. The real leader at the siege of Thebes, he slays the Theban king, Laodamas, and is the first to enter the conquered city. On returning home, he, at the bidding of the Delphian Apollo, avenges his father by slaying his mother, with, or according to some accounts, without, his brother's help; but immediately, like Orestes; he is set upon by the Erinyes, and wanders distracted, seeking purification and a new home. Phegeus, of the Arcadian Psophis, half purifies him of his guilt, and gives him his daughter Arsinoe or Alphesiboea to wife, to whom he presents the jewels of Harmonia, which he has brought from Argos. But soon the crops fail in the land, and he falls into his distemper again, till, after many wanderings, he arrives at the mouth of the Achelous, and there, in an island that has floated up, he finds the country promised by the god, which had not existed at the time of his dying mother's curse, and so he is completely cured. He marries Achelous' daughter, Callirrhoe, by whom he has two sons, Acarnan and Amphoterus. Unable to withstand his wife's entreaties that she may have Harmonia's necklace and robe, he goes to Phegeus in Arcadia, and begs those treasures of him, pretending that he will dedicate them at Delphi for the perfect healing of his madness. He obtains them; but Phegeus, on learning the truth, sets his sons to waylay him on his road, and rob him of his treasure and his life; and then Alcmaeon's two sons avenge their father's death on these murderers. Alcmaeon, like his father, received divine honours after death; he had a sanctuary at Thebes, and at Psophis a consecrated tomb.