The last High King of Ireland (1011). He had previously made himself ruler of Munster and Limerick in southern Ireland. In doing so Brian, ruler of the Dal Cais dynasty of Munster, overcame the influence of the powerful Uú Néill dynasty which had dominated Ireland for three centuries. In 1012 the men of Leinster, supported by the Norse settlers of Dublin, rose in revolt. The Battle of Clontarf brought victory to Brian’s forces, though he was killed in the fighting.