The Chronicle of the Princes of Wales records that "Angharad daughter of Owain son of Edwin was the wife of Gruffudd son of Cynan" and mother of "Cadwallon and Owain and Cadwalader and of many daughters". Gerald of Wales´s Descriptio Kambriæ records the descent of the rulers of North Wales in reverse chronological order as follows: “David filius Oenei, Oeneus filius Griphini, Griphinus filius Canani, Cananus filius Iago, Iago filius Ythewal, Ythewal filius Meuric, Meuric filius Anaudrech, Anaudrech filius Mervini, Mervinus filius Roderici magni”. The Chronicle of the Princes of Wales records that "Owain and Cadwalader the sons of Gruffudd son of Cynan led a large and cruel army into Ceredigion" in 1135.
King of Gwynedd. He changed his title from King to Prince .
Robert of Torigny records the death in 1171 of "rex Oenus avunculus eius" (referring to "Ris rex Walensium"). The Chronicle of the Princes of Wales records that "Owain Gwynedd son of Gruffudd son of Cynan, prince of Gwynedd" died in Nov 1169. 2
The existence of another Owain ap Gruffydd , known as Owain Cyfeiliog, explains the use of the distinctive style of ‘ Owain Gwynedd.’....
As a young man during the decade 1120-30 he was associated with an elder brother, Cadwallon..., in restoring the prosperity of Gwynedd on behalf of an ageing father, and in directing the military operations which added the cantrefs of Meirionydd, Rhos, Rhufoniog, and Dyffryn Clwyd to Gwynedd proper. Thus on his accession to full kingship on Gruffudd 's death in 1137 (Cadwallon d. in 1132) the groundwork of a great career had been firmly laid. Already political anarchy in England had provided the opportunity to combine with Gruffydd ap Rhys and others in a victory over the Normans at Crug Mawr (1136), and in the temporary occupation of Ceredigion. Owain 's operations in South Wales, however, were in the main intended as diversionary measures to cover his main objective of territorial consolidation in North Wales. Eventually, despite the opposition of Ranulf of Chester and Madog ap Maredudd of Powys, Mold and its hinterland submitted to him, in 1146, and in 1149 Tegeingl and Iâl were annexed to Gwynedd. In 1157, with changed conditions in England, Owain suffered his only decisive reverse at the hands of Henry II. The expedition into North Wales undertaken by Henry in that year, though indecisive in its military results, marks a positive stage in the relations of England and Wales. Deprived of Tegeingl and Iâl, and forced to re-admit his younger brother, Cadwaladr, exiled in 1152, to a share of power in Gwynedd. Owain, with characteristic prudence and insight, realised the great potentialities of the Angevin monarchy, did homage to Henry, and apparently agreed to change his official style from ‘ king ’ to ‘ prince.’ He made no attempt, moreover, to break the feudal link with England, when at the climax of his career, after the general Welsh uprising of 1165, he destroyed the royal strongholds of Tegeingl and once more established the power of Aberffraw along the estuary of the Dee. He d. on 28 Nov. 1170 , and was buried in the cathedral church of Bangor.
Though it was Owain who finally accepted the principle of Angevin overlordship over Gwynedd, he regarded himself as no ordinary vassal (his attitude to episcopal elections in the see of Bangor should be noted) and it is clear that it was he who gave initial direction to the policies of his successors. It was largely due to his example, moreover, that the native rulers of Wales ceased to be mere tribal chieftains and took their place alongside the great feudal magnates of the time. The praises so repeatedly accorded to his many personal qualities by contemporary poets, and indeed by several public figures who could not have been predisposed in his favour, have so genuine a tone about them that the progressive trends in all the arts of peace and war discerned in 12th cent. Wales , it must be concluded, were in large measure due to the fostering genius of ‘ Owain the Great .’ 3