Gwynedd throws his former kingdom into disarray and causes a power struggle in Gwynedd; within weeks, his nominated heir is dead, and his son Dafydd ab Owain assumes power. Dafydd is, however, unable to maintain his father's hold on south Wales, which falls under the aegis of Rhys ap Gruffydd. Court poet Cynddelw Brydydd Mawr produces his well-known elegy to Owain. Owain Cyfeiliog establishes the Cistercian monastery of Strata Marcella. Peter de Leia becomes Prior of Much Wenlock. According to folklore, Madoc (Owain's illegitimate son) sails from Wales to America. 1171 September - The Lord Rhys negotiates a lasting peace with King Henry II of England. October - King Henry II of England makes a pilgrimage to St David's. Iorwerth ab Owain, having fallen out of favour with King Henry II, loses the lordship of Caerleon. 1172 Philip de Braose is given the “honour” of Limerick, in recognition of his service to the English king in Ireland. Gerald of Wales completes his studies at the University of Paris and returns to Britain. He is soon commissioned by the Archbishop of Canterbury to enforce the payment of tithes on wool and cheese in the diocese of St David's. In the same year David Fitzgerald, the bishop, is granted a royal charter confirming all his possessions. Following the death of his son Owain at the hands of the Earl of Gloucester, Iorwerth ab Owain rebels against Norman rule. 1173 Maelgwn ab Owain Gwynedd, one of the sons of Owain Gwynedd, is driven into exile in Ireland by his brother Dafydd. Dafydd sides with the King of England against the Welsh rebels and seeks the hand of Henry's half-sister Emma of Anjou in return for his assistance. Iorwerth ab Owain and his son take Caerleon and other castles in Gwent. 1174 Maelgwn ab Owain Gwynedd returns from exile and is imprisoned by his brother Dafydd, who proceeds to eliminate all opposition to his rule in Gwynedd, including his brothers Rhodri, Cynan and Iorwerth Drwyndwn; Cynan and Iorwerth are both believed to have died during this year. Dafydd marries Emma of Anjou during the summer. Richard de Clare, 2nd Earl of Pembroke, takes Usk Castle. 1175 18 May – David FitzGerald, Bishop of St David's, attends the council of Richard, Archbishop of Canterbury in London, in the presence of King Henry II of England and Henry the Young King. 12 October – Adam Parvipontanus