In the 1980s cartoon series, Skeletor is a former pupil of Hordak, leader of the Evil Horde. When Hordak invaded Eternia and kidnapped one of the King and Queen's twin babies from the palace, Man-At-Arms and the Royal Guard captured his apprentice, Skeletor, and forced him to divulge the whereabouts of his master, who had retreated to his base of operations, Snake Mountain. When cornered, Hordak opened a random dimensional portal (later revealed to have led to Etheria) and leaped through with the baby Princess Adora in his possession. Skeletor remained on Eternia, raised an army of powerful minions of his own and took over as ruler of Snake Mountain. Skeletor's main goal is to conquer the mysterious fortress of Castle Grayskull, from which He-Man draws his powers. If he succeeds, Skeletor would be able to conquer not only Eternia, but the whole universe. At the same time, his other goal is to take revenge on Hordak and overthrow Horde Prime in his bid to conquer the universe.