The Mares of Diomedes, also called the Mares of Thrace, were a herd of man-eating horses in Greek mythology belonging to the giant Diomedes. The Mares, which were the terror of the region of Thrace, were kept tethered by iron chains to a bronze manger and were named Podargos (the swift), Lampon (the shining), Xanthos (the yellow) and Deinos (the terrible). Heracles (Hercules) defeated these monsters in his eight labor. He fed Diomedes, their master, to his own horses and while they were occupied with their human meal, Heracles found the opportunity to bind their mouths shut.
