Which hero was the father of the hero Diomedes?

The father of the hero Diomedes was Tydeus. In Greek mythology, Tydeus was an Aetolian warrior whose fame—and tragic death—shaped his son’s heroic legacy.

Tydeus was the son of Oeneus, king of Calydon, and married Deipyle, the daughter of King Adrastus of Argos. After being exiled from Calydon for killing relatives, he found refuge at Argos. There he became one of the leaders of the Seven against Thebes, an expedition intended to restore Polynices to power.

Tydeus was a formidable fighter, but he was mortally wounded during the war by Melanippus. In a famous later version, Athena planned to make him immortal. She abandoned that plan after Tydeus devoured the brains of his slain enemy, an act that horrified the goddess.

Diomedes was still young when Tydeus died, yet he later joined the Epigoni and fought at Troy. Homer often identifies Diomedes as Tydides, literally “son of Tydeus.” Telamon, Peleus, and Atreus were fathers of other prominent figures, not Diomedes.