Llywelyn Bren (), or Llywelyn ap Gruffudd ap Rhys / Llywelyn ap Rhys (also Llewelyn) or in . He was a nobleman who led a 1316 revolt in Wales in the reign of King Edward II of England. It marked the last serious challenge to English rule in Wales until the attempts of Owain Lawgoch to invade with French support in the 1370s. Hugh Despenser the Younger's unlawful execution of Llywelyn Bren helped to lead to the eventual overthrow of both Edward II and Hugh. Lineage Llywelyn Bren was a Welsh nobleman of the minor royal house of the cantref of Senghenydd, (previously Cantref Breiniol) and Miscin, and was also a descendant of Ifor Bach, his great-grandfather. His father was Gruffudd ap Rhys. Llywelyn is thought to have been born before 1267, as Gruffudd was dispossessed of the lordship of Senghenydd in that year by Gilbert de Clare, 7th Earl of Gloucester and then imprisoned in Ireland. There is no record of him returning to Wales. Llywelyn married Lleucu (died 1349). They produced at least seven sons, who also took part in the revolt. Background of the revolt Before the outbreak of Llywelyn's revolt in 1316, there had already been violence in the Welsh Marcher lands of south-east Wales. The Battle of Bannockburn in June 1314 marked the death of Gilbert de Clare, 8th Earl of Gloucester the Lord of Glamorgan. He had been the most prominent landowner in the south and his death left a regional power vacuum. There was a heavy-handed response from the English Crown to overseeing De Clare's lands. That combined with the death of several hundred men of Glamorgan at Bannockburn caused a revolt in the lordship in late summer that year. Llywelyn seems not to have taken part. The revolt appears to have ended when King Edward II of England appointed Bartholomew de Badlesmere, as royal custodian in Glamorgan. Revolt and siege of Caerphilly Castle In 1315, Edward II, as guardian of the three sisters and heiresses of the estate of Gilbert de Clare, 8th Earl of Gloucester, replaced de Badlesmere with a new English administrator, Payn de Turberville of Coity Castle was appointed as replacement () to Earl de Clare. Bren had previously had office under the Earl who he considered a friend. Payn persecuted the Glamorgan people, who were then, like many in northern Europe at the time, in the throes of