Hades is the son of Cronos and Rhea, he is the brother of Zeus and Poseidon. He is the ruler of the Underworld. He was married to Persephone. He was known as Pluto (lord of riches). He is one of the six Olympians. The underworld was called Hades. The underworld was divided into two parts, Erebus and Tartarus. Tartarus was a deeper part of the underworld where Titans were imprisoned. Erebus means darkness and also was the gloomy region which the dead were thought to pass before going into Tartarus.