Son of Magaat and nephew of the Saxon King Aminaduc, and brother of one of the kings of Ireland.

As part of the Saxon invasion of Britain at the beginning of Arthur's reign, this Saxon king of Denmark was assigned the task of plundering Lothian and Orkney. He was present at the battle of Clarence, the razing of Cardueil, and the plundering of Caradigan. Arrant was killed in battle beside the Humber along with his four allies, the kings of Ireland, Vale, Soleise, and the Isle of Longtains.