Hades
In Greek Mythology, Hades is the god of the Underworld. He was the son of Chronos and Rhea, brother of Poseidon and Zeus. Only after Zeus had established his reign as supreme deity, did Hades become the God of the Underworld. He was part of the original twelve Olympian Gods. Later on, he was replaced by Aphrodite as a member of the Olympian Council, and he withdrew into his underworld.
In Roman mythology, he was called Pluto.