Tydeus was a son of Oeneus and either Periboea, Oeneus's second wife, or Gorge, Oeneus's daughter. He was the husband of Deipyle, the mother of Diomedes. Tydeus was banished from Calydon by his uncle Agrius, because he killed either his brother or a different uncle or six of his cousins. He travelled to Argos, where he married Deipyle, daughter of king Adrastus.
While housing Tydeus, King Adrastus of Argos also lodged Polynices, the exiled son of Oedipus who had shared the rule of Thebes with his brother Eteocles before he was expelled by the latter. Late one night, the two young exiles got into a fierce dispute over the guest room in Adrastus's palace. Awakened by the clamor, Adrastus rushed to the hall to find the two menlocked in a brawl. It was then that Adrastus recalled a prophecy that had instructed him to “yoke his daughters to a boar and a lion”. Adrastus recognized Tydeus as the boar and Polynices as the lion and wed his daughters to them, keeping them as his sons-in-law in Argos. Through marriage into Adrastus's family, Polynices and Tydeus became princes of Argos, had children, and generally lived well. Adrastus promised that he would help restore their kingdoms to them ) and he orchestrated the construction of the seven armies that became known as Seven Against Thebes. The armies were raised from Argolis, the largest army that had ever appeared in Greece till that time.
Shortly after the expedition arrived in Nemea, the young son of King Lycourgos was killed by a snake. In turn, Adrastus's men killed the serpent, buried the boy and held the first Nemean Games in his honor. Tydeus won the boxing event at these games.
Envoy to Thebes
When the expedition reached Cithaeron, Tydeus was sent ahead to demand that the Thebans reinstate Polynices. Frustrated with being ignored by Eteocles, Tydeus issued one-on-one challenges to multiple men and vanquished each one with power granted to him by Athena. While Tydeus returned to his allies, the Thebans amassed a force of fifty men, led by Maeon and Polyphontes, and ambushed him. Tydeus killed every man with the exception of Maeon, whom he allowed to live due to signs from the gods.
In literature and art
The 7th century poet Mimnermus attributes the murder of Ismene, the sister of Antigone, to Tydeus. No other Classical writer mentions the story, but the scene is represented on a 6th-century Corinthian black-figureamphora now housed in the Louvre. Tydeus also appears in Aeschylus's play Seven against Thebes, as one of the "Seven", and in the same guise in Euripides' play The Phoenician Women. He faced off with the defender Melanippus and killed Melanippus, but was mortally wounded himself. In other versions of the myth, the detail is added that the goddess Athena had planned to make him immortal but refused after Tydeus in a hubristic fit devoured the brains of the defeated Melanippus. Tydeus is mentioned multiple times in the Iliad. One of the most notable mentions is in Book IV where Agamemnon reminds Diomedes of the deeds of his father Tydeus. Agamemnon recites the events told in the section above.
