Hades is the God of the Underworld. He is the brother of Zeus and the uncle of Hercules.
After his father Cronus appoints Zeus as the next ruler of Mount Olympus, he kills him. Zeus then stops his heart from beating and banishes him to the Underworld to be its ruler.
One day, he appeared before Liam Jones and offered to let the ship sink in exchange that Liam and Killain be spared and the Eye of the Storm will be in their possession.
Years later, he meets Zelena in the Land of Oz and was interested in her time travelling spell. He fell in love with her but Zelena saw it as a trick and asked him to go back to the Underworld.
When Emma and her allies arrive in the Underworld, he forces Cora to get rid of the heroes from his land. Failing, he turns Cora back into a miller and forces her to work at an underground mill for her failure. After Hercules and Megara ascend to Mount Olympus, Hades decides to trap the heroes in the Underworld by forcing Hook to write a new name on a gravestone for each souls that leaves. When Hook refuses, he hangs Hook over the River of Lost Souls. He also sends Captain Silver to the Worst Place and tries sending Hook, later Liam, there but fails. He also buys the contract made by Rumplestiltskin years ago with Fendrake, threatening to take Mr. Gold's second unborn child with Belle. He is later reunited with Zelena, who falls in love with him. When she gets kidnap, he asks Emma's help to get her back. Later, after his heart starts beating again due to true love's kiss, a portal is opened. He turns over the Underworld to Cruella as he leaves for Storybrooke with Zelena and her child. There, he kills King Arthur and hopes to take over Storybrooke. Using the Olympian Crystal, he kills Robin Hood. Zelena then kills him with the Olympian Crystal.