son of Tydeus and Diephyle, was king of Ætolia, and one of the bravest of the Grecian chiefs in the Trojan war. He often engaged Hector and Æneas, and obtained much military glory. He went with Ulysses to steal the Palladium from the temple of Minerva in Troy; and assisted in murdering Rhesus, king of Thrace, and in carrying away his horses. On his return from the siege of Troy he lost his way in the darkness of night, and landed in Attica, where his companions plundered the country, and lost the Trojan Palladium. During his long absence, his wife Ægiale forgot her marriage vows, and prostituted herself to Cometes, one of her servants. This lasciviousness of the queen was attributed by some to the resentment of Venus, whom Diomedes had severely wounded in a battle before Troy. The infidelity of Ægiale proved highly displeasing to Diomedes. He resolved to abandon his native country, which was the seat of his disgrace; and the attempts of his wife to take away his life contributed, according to some accounts, to hasten his departure. He proceeded to that part of Italy afterwards named Magna Graecia, where he built a city, which he called Argyrippa, and married the daughter of Daunus, the king of the country; and he died there in extreme old age, or, according to a certain tradition, he perished by the hand of his father-in-law. His death was greatly lamented by his companions, who in the excess of their grief were changed into birds resembling swans, which took flight into a neighbouring island in the Adriatic, and became remarkable no less for the tameless with which they approached the Greeks, than for the horror with which they shunned all other nations. They were called the birds of Diomed. Altars were raised to Diomedes as to a god, one of which Strabo mentions at Timavus.