In Greek mythology, King Oenomaus (Ancient Greek: Οἰνόμαος) of Pisa in Elis — the territory that held Olympia — was father of Hippodamia and, in most accounts, a son of Ares. Fearful of a prophecy that a son-in-law would kill him, he raced Hippodamia's suitors and slew those he overtook until Pelops, aided by the charioteer Myrtilus, wrecked his chariot. His death and Pelops's funeral games are one legendary origin of the Olympic Games.
Adapted from Wikipedia, "Oenomaus" · CC BY-SA 4.0
I.Family
Oenomaus's mother is variously the naiad Harpina (daughter of Asopus), the Pleiad Sterope/Asterope, or Eurythoe daughter of Danaus; Pausanias, sceptical of divine descent, makes him son of the mortal Alxion. His wife is Sterope in some sources, elsewhere Evarete of Argos or Eurythoe. Besides Hippodamia he is father of Leucippus (who dies for love of Daphne) and Alcippe (mother of Marpessa by Evenus). Euripides places him two generations before Troy as great-grandfather of Agamemnon and Menelaus.
II.Suitors' race and death
An oracle warned that he would die by his son-in-law's hand; alternatively, some say he loved Hippodamia himself and would not give her away. He challenged each suitor to a chariot race — his own team divinely swift — and killed the losers, affixing their heads to the wooden columns of his palace. Pausanias was shown a last standing column and lists eighteen named victims for whom Pelops later raised a monument.
Pelops arrives with Poseidon's winged horses; Myrtilus, Oenomaus's charioteer and son of Hermes, is bribed to replace the bronze linchpins with beeswax. As Oenomaus closes to spear Pelops, the wheels fly off and he is dragged to death. Myrtilus survives only to be killed by Pelops, cursing the Pelopid house as he dies. In memory of the race — or of Pelops's victory — the Olympic Games are said to begin; Elean legend preserved a burnt "house of Oenomaus" and a turning-post at Olympia.