Mnemosyne — Classical Greek Myth Library

The eighth labor sent Heracles to Thrace for the mares of Diomedes, king of the Bistones. Those horses were savage and man-eating, stalled with iron mangers and chained with iron. Heracles sailed with volunteers, overpowered the grooms, and drove the mares to the sea. Leaving them in the care of Abderus—a son of Hermes from Opus in Locris, and his beloved—he turned to fight the Bistones who came in arms under Diomedes. The mares dragged Abderus to death and began to devour him. Heracles, defeating the Bistones and killing Diomedes, found what remained of his friend, founded the city Abdera beside the grave, and then fed Diomedes’ body to the mares, which thereafter grew tame enough to be bridled. He brought them to Eurystheus. The king released them; they wandered to Olympus’s slopes and there were destroyed by wild beasts. The labor thus combines a monstrous animal-capture with a Thracian war, the death of a companion, and a civic foundation-aetiology—Abdera as memorial—before the usual Mycenaean delivery and disposal.