Hades, God of the Underworld, Lord of the Dead in Greek Mythology Explained, Hades (whose name means “the invisible”) is the Greek god of the underworld, the realm of the dead. He was the son of Cronus and Rhea and the brother of Zeus, Poseidon, Hera, Demeter and Hestia. He forcibly married Persephone, Demeter’s daughter. In the division of the universe after the overthrow of their father, Zeus took the sky, Poseidon the sea, and Hades the underworld; the earth is divided between them. Another name for Hades is Polydegmon (“receiver of many guests”) because of the many people who have died and come to his kingdom.