Fell Diomed, whose horses fat with gore,
His subjects bodies in their mangers tore,
He next o'erthrew. And as old authors say,
The Tyrant gave to his own steeds a prey,
On Mount Olympus rent by savage beasts,
No more the horses make on man their horrid feasts.
The Mares of Diomedes were four man-eating horses in Greek mythology. Magnificent, wild, and uncontrollable, they belonged to the giant Diomedes, king of Thrace, a son of Ares and Cyrene who lived on the shores of the Black Sea. Bucephalus, Alexander the Great's horse, was said to be descended from these mares.
One of the Twelve Labours of Heracles was to steal the Mares.