The Chronicle of the Princes of Wales records that "Gruffudd son of Rhys son of Tewdwr, king of South Wales, came from Ireland to Dyved…returned to his patrimony" in 1112 adding that he "passed about two years, sometimes with Gerald steward of Pembroke Castle, his brother-in-law who had married his sister Nest…". The Chronicle of the Princes of Wales records that "Rhys son of Tewdwr began to reign" in 1077. Gerald of Wales´s Descriptio Kambrić names “descendientes...a Theodoro...Resus filius Theodori, Griphinus filius Resi, et Resus filius Griphini qui hodie praest” as successive rulers in South Wales. Florence of Worcester records that "Griffinus filius Res" plundered castles in Wales in 1116 in protest at Henry I King of England not allowing him to inherit part of his father's territories.
He succeeded in 1135 as King of Deheubarth.
The Continuator of Florence of Worcester records that "rex Waliee Griffinus filius Res" was murdered in . The Annales Cambrić record the death in 1137 of "Grifinus Resi filius". The Chronicle of the Princes of Wales records that "Gruffudd son of Rhys" died in 1136. 1
"When the old South Wales monarchy disintegrated on the fall of Rhys ap Tewdwr in 1093 , Gruffydd , the infant heir, was taken to Ireland where he was given asylum during childhood and early manhood. When he returned in 1113 , the patriotic support of his younger countrymen was made useless by the cautious conduct of elements as yet indisposed to resist the Norman monarchy, including Gruffudd ap Cynan who was prepared to hand his young kinsman over to Henry I when in 1115 he sought sanctuary in Gwynedd . The failure of the resistance movement which reached its climax in the open rebellion of 1116 was inevitable. Gruffydd ap Rhys nevertheless reached an accommodation with Henry and was given land in the commote of Caeo . Apart from a brief intermission in 1127 , involving a second exile in Ireland , he appears to have lived a quiet existence there until after Henry 's death. There also no doubt were b. Maredudd and Rhys , his sons by Gwenllian , daughter of Gruffudd ap Cynan , Anarawd and Cadell being evidently children of an earlier union. In the general revolt which spread throughout Wales when Henry d., he took a prominent part, being present at the decisive battle of Crug Mawr in 1136 . In the following year he d., predeceased by the redoubtable Gwenllian..." 2