Hades is the underworld, a “geographical” area. The god of Hades was Pluto. Of course, in the protohistoric age, the mythology named him Hades, but during ancient and mediaeval times, he was named Pluto. He was one of the three strongest gods, among his brothers Zeus, the king of Olympus and father of gods and mortals alike, and Poseidon, the lord of the seas. His wife was Persephone, daughter of Demeter, goddess of grainwork, and he was NOT an Olympian god, even though he was one of the most powerful gods, because he was not living in Olympus
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