Roderic the Great, or Rhodri Mawr, who was king over all Wales, was the cause of this division. He had three sons, Mervin, Anarawt, and Cadell, amongst whom he partitioned the whole principality. North Wales fell to the lot of Mervin; Powys to Anarawt; and Cadell received the portion of South Wales, together with the general good wishes of his brothers and the people--by Geraldus Cambrensis.