Poseidon was the great Olympian god of the sea, earthquakes and horses. Although he was officially one of the supreme gods of Mount Olympus, he spent most of his time in his watery domain. Poseidon is the brother of Zeus. After the overthow of their Father Cronus, he drew lots with Zeus and Hades for shares of the world. His prize was to become lord of the sea. Zeus became the god of the sky and Hades the ruler of the underworld.