As a son of Budic, he was recorded as a nephew of Arthur. He was said to have visited Arthur's court during his early exile and to have returned to help Arthur against the Saxons after the family's restoration in Brittany. Landing at Southampton, his army was credited with assisting Arthur at the Battle of Dubglas, the Siege of Caer Ebrauc (i.e. York), and the Battle of Cat Celidon Coit. It was then bottled up and besieged in turn at Dumbarton Castle ("Caer-Brithon"). Hoel was also said to have been at the Battle of Badon before conquering France for Arthur, who then moved his court to Paris. Finally returning to Brittany, he was aided by Tristram of Lyonesse in suppressing a civil war.