Hades is the Greek God of the Underworld and of the Dead. He is the brother of Zeus and Poseidon, but unlike the other Olympians, he only resides in the Underworld and rarely surfaces.
He takes Persephone as his queen after forcefully snatching her from her mother Demeter. He retains her until finally Hermes is sent down to release her. However, Hades fed her a pomegranate seed before her release, and this required that she come back down to the Underworld with Hades every winter.