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 13th century History of Gruffydd ap Cynan records that he was born in Dublin, son of "Cynan king of Gwynedd and his mother Ragnaillt daughter of Olaf King of the city of Dublin". The Chronicle of the Princes of Wales records that "Gruffudd son of Cynan fought against the men of Iago and of Mona, and the Gwyneddians killed Cynvrig son of Rhiwallon" in 1073. According to the 13th century History of Gruffydd ap Cynan, Gruffydd defeated "Trahaiarn son of Caradoc and Cenwric son of Rhiwallon, Kings of Powys and all Gwynedd" and, with help from "Robert of Rhuddlan…nephew to Hugh Earl of Chester" imposed himself as king of Gwynedd after prevailing at the battle of "Gwaet Erw". None of these alleged exploits are recorded the Annales Cambriæ or the Chronicle of the Princes of Wales, and it is uncertain how accurate the History can be given its late date. The Chronicle of the Princes of Wales records that "Cadwgan son of Bleddyn and Gruffudd son of Cynan left the isle of Mona and retreated into Ireland for fear of the treachery of their own men" in 1096. The Chronicle of the Princes of Wales records that "Cadwgan son of Bleddyn and Gruffudd son of Cynan returned from Ireland" in 1097 and "made peace with the French…[and] retained part of the country…Gruffud obtained Mona". The 13th century History of Gruffydd ap Cynan records the death of Gruffydd ap Cynan aged 82 ... and his burial at Bangor. 1
Son of Cynan ap Iago, who was an exile in Ireland, and Rhagnell ( Ragnhildr ), a daughter of the royal house of the Scandinavians of Dublin . After 1039, when Iago was treacherously slain by his own men, Gwynedd was ruled by usurpers who were not of the royal line. One of these was Bleddyn ap Cynfyn, who was killed in 1075 and succeeded by his cousin, Trahaearn ap Caradog, king of Arwystli. In that same year Gruffudd crossed over from Ireland intent on regaining his patrimony, and landed at Abermenai. With the help of Robert of Rhuddlan he overcame and killed Cynwrig, who held Llyn under Trahaearn. Trahaearn himself was conquered in a battle fought somewhere in Meirionnydd and compelled to retreat to his own lands of Arwystli. As king of Gwynedd Gruffudd 's first act was to attack the Norman castle at Rhuddlan in spite of the former help given him by Robert, carrying off booty but failing to take the castle itself. As a result of the resentment felt towards the Norsemen in Gruffudd 's army the men of Llyn rebelled, giving Trahaearn an opportunity to attack Gruffudd and overcome him in a battle which took place at Bron-yr-erw near Clynnog. Gruffudd fled to Ireland. In 1081 he returned and landed at Porth Clais in Dyfed, where he was joined by Rhys ap Tewdwr, another exile, who was laying claim to his patrimony in Deheubarth. They met Trahaearn at Mynydd Cam, where he was slain, Gruffudd thus becoming again king of Gwynedd. Soon after, however, through the treachery of Meirion Goch, one of his own men, he was captured by the Normans at Rug near Corwen and taken prisoner to Chester. During his imprisonment the Normans gained much land in Gwynedd, and built castles at Bangor, Caernarvon and Aberlleiniog (near the later Beaumaris). It cannot now be stated with certainty how long Gruffudd remained a prisoner (the History at one point says twelve years and at another sixteen years), but he was free by 1094 (and perhaps some years earlier) because he was prominent in the general insurrection against the Norman power which took place that year. But in 1098 the Normans made a concerted attack upon Gwynedd from Chester and Shrewsbury. Gruffudd was shut up in Anglesey and compelled once more to seek refuge in Ireland. He returned however the following year and was allowed to rule over Anglesey with the consent of the Normans. Sometime in the course of the succeeding years he made himself lord of Gwynedd uwch Conwy, and for the rest of his life he was left undisturbed to consolidate his kingdom. It is true that Henry I led a formidable army into Gwynedd in 1114, but Gruffudd lost no land, and after this he himself did not fight a single battle. The authority of Gwynedd was however greatly extended by his sons, Owain and Cadwaladr, and before Gruffudd 's death Ceredigion, Meirionnydd, Rhos, Rhufoniog and Dyffryn Clwyd were under the rule of Gwynedd. He d., blind and decrepit, in 1137, and was buried in the cathedral church of Bangor. An elegy upon him was sung by Meilyr, his pencerdd. His wife, Angharad, daughter of Owain ab Edwin, survived him by twenty-five years.
It was part of the traditional lore of the Welsh bards that Gruffudd ap Cynan had made certain regulations to govern their craft, and his name was used to give authority to the ‘statute’ drawn up in connection with the Caerwys eisteddfod of 1523. There is nothing to substantiate this tradition, but it is not unreasonable to suggest that Gruffudd may have brought bards and musicians with him from Ireland and that these may have had some influence on the craft of poetry and music in Wales. He may also have made some formal changes in the bardic organization. It is clear that a genuine and persistent tradition to this effect existed in the 16th cent. It is perhaps worth noting that the History mentions the death in battle of Gellan, Gruffudd 's harpist, in 1094 .
Gruffudd ap Cynan is the only mediaeval Welsh prince whose biography, in the form of pure eulogy, has survived.... Linguistic characteristics prove it to have been a translation of a Latin original now lost. It was probably written by a cleric towards the end of the 12th cent. 2