A son of Oeneus and Periboea (Gorge or Althaea), was the husband of Deïpyle, by whom he became the father of Diomedes ; he was king of Calydon, and one of the princes who joined Polyneices in the expedition against Thebes. (Apollod. i. 8. § 5; Hom. Il. ii. 406, xiv. 115, &c.) Tydeus was obliged to flee from his country in consequence of some murder which he had committed, but which is differently described by the different authors, some saying that he killed his father's brother, Melas, Lycopeus, or Alcathous ; others that he slew Thoas or Aphareus, his mother's brother; others that he slew his brother Olenias, and others again that he killed the sons of Melas, who had revolted against Oeneus (Schol. ad Stat. Theb. i. 280, 402). He fled to Adrastus at Argos, who purified him from the murder, and gave him his daughter Deïpyle in marriage. With Adrastus he then went against Thebes, where he was wounded by.Melanippus, who, however, was slain by him. (Apollod. l. c. ; Eustath. ad Hom. pp. 288, 971.) When Tydeus lay on the ground wounded, Athena appeared to him with a remedy which she had received from Zeus, and which was to make him immortal. This, however, was prevented by a stratagem of Amphiaraus, who hated Tydeus, for he cut off the head of Melanippus and brought it to Tydeus, who cut it in two and ate the brain, or devoured some of the flesh. (Schol. ad Pind. Nem. x. 12; comp. Eustath. ad Hom. p. 1273.) Athena seeing this, shuddered, and did not apply the remedy which she had brought. (Apollod. iii. 6. § 8.) Tydeus then died, and was buried by Maeon. (Paus. ix. 18. § 2; Comp. ADRASTUS; AMPHIARAUS.)