Llywelyn ap Iorwerth, (Llywelyn Fawr or Llywelyn the Great: 1173-1240) can justly be called the greatest of the medieval Welsh kings. By 1202, he had taken advantage of the quarrels of his uncles and had become ruler of the kingdom of Gwynedd. Further successes in Deheubarth, after the death of the Lord Rhys, and in Powys made him the most powerful of all the Welsh rulers, though it was Gruffudd ap Llwyelyn who is remembered as the only native monarch to rule over all of Wales. Peter N. Williams, Ph.D.