Amphiaraus, a mythical hero and seer of Greece, the son of Oicles and Hypermnestra. He was married to Eriphyle, sister of Adrastus, king of Argos, by whom he had numerous sons. Having sworn that he would abide by the decision of his wife on any difference which might arise between himself and Adrastus, Eriphyle took advantage of this oath to force Amphiaraus to join in the enterprise of the seven against Thebes. Before setting out he made his sons promise to punish her treachery. (See Alcmaeon.) At the siege of Thebes he greatly distinguished himself, but being pursued by Periclymenus, he fled toward the river Ismenius, where the earth opened and swallowed him. Jupiter made him immortal. An oracle of Amphiaraus, near Thebes, enjoyed great reputation among all the Greeks.