Korg is part of the Kronan race seen in "Journey into Mystery" #83. After his defeat at the hands of Thor when the Stone Men tried to invade Earth, Korg became a prisoner of the Red King on the alien planet of Sakaar. He was forced into slavery by an obedience disk and made to fight for his life in the gladiatorial arenas. Korg was made to kill his brother Margus against his will, a fact that continues to haunt Korg.