Hades, in the ancient Greek religion and myth, is the god of the dead and the king of the underworld, with which his name became synonymous. Hades was the eldest son of Cronus and Rhea, although the last son regurgitated by his father. He and his brothers, Zeus and Poseidon, defeated their father's generation of gods, the Titans, and claimed rulership over the cosmos. Hades received the underworld, Zeus the sky, and Poseidon the sea, with the solid earth, long the province of Gaia, available to all three concurrently. Hades was often portrayed with his three-headed guard dog Cerberus.