© Region of Eastern Macedonia and Thrace
According to the ancient tradition from Homer and on, Ares originated from Thrace. Homer mentions that Ares was born and lived in Thrace because Zeus wanted to keep him away from the other Olympian gods. Herodotus mentions that the Thracians worshipped three divinities, Ares, Dionysus and Artemis, and that for the Scythians, who lived further east, Ares was the most important god who was worshipped as the form of a sword. The Thracians, who were famous for their barbarian and warlike character, worshipped the fierce god of the battles with special honours as well as his equally strong and barbarian descendants, Tereus, Lycurgus and Diomedes.
Diomedes was a son of Ares and Cyrene, and the brother of Cycnus. He was ruling the Thracian tribe of the Bistonians, famous for their savage and warlike character, who lived around the lake Bistonis. Diomedes was famous for his four, extremely wild, man-eating mares that he fed with foreigners and unsuspicious travellers that passed through his kingdom or with any of his subjects that he wished to punish. Because those horses were so wild and dangerous, Diomedes kept them tied with strong iron chains and had placed heavy-armed guards around their stable to watch them over.
The eighth labour of Heracles was to deliver alive these man-eating horses to Eurystheus. According to Apollodorusĺ version of the myth, Heracles equipped a ship before this enterprise and asked many famous heroes to assist him. A lot of brave men were willing to help him, among them Abderus, an intimate friend of Heracles, son of Heremus and Thronia from Opus in Locris. After several days of travelling, Heracles and his company arrived at Thasos and from there to the opposite coast. When they arrived at the palace of Diomedes and the stables where the horses were kept, Heracles killed all the guards, took the horses to the shore near the ship and assigned Abderus to watch them over. Diomedes, after finding out that the guards were killed and the horses were stolen, ordered the Bistonians to run after the invaders. A wild fight took place during which Heracles killed Diomedes and many of his guards with his club. After the death of their king, the Bistonians were forced to retreat in order to escape. When Heracles returned to the shore and to the ship he found something terrible; the wild horses had devoured Abderus. Full of sorrow, Heracles buried his friend at this very site where he built a city naming it Abdera and instituted annual games in his honour.
Heracles delivered the horses to Eurystheus who let them free. According to the myth, the wandering horses arrived at mount Olympos where they were finally devoured by other wild beasts.
There are many version of the myth, some of them having that Heracles did not deliver the horses to Eurystheus, but that he killed them or that the horses were tamed and that their descendants persisted until the times of Alexander the Great.