When King Urragon III Greyiron died, a Kingsmoot was urgently called by members of his family, as one of his sons, Torgon Greyiron, was away raiding the Mander. The old king's younger sons were hoping to be chosen, but the Ironborn instead chose Urrathon. His first act was to put all the present sons of the old king to death, earning the nickname Badbrother.
He ruled for two years, and earned many enemies due to his cruelty. Torgon, the only surviving son of the old king, returned to the Iron Islands and declared the Kingsmoot unlawful. The people, priests, and captains agreed, with Urrathon being hacked to death.