The problems related to the authenticity of the Gwentian Chronicle were discussed by Thomas Stephens in the mid-19th century and more recently G. Extracts from the Gwentian Chronicle are included in square brackets in the present document to highlight the potential difficulty.As will be seen, without these extracts many parts of the reconstruction of the families of the Welsh princes and kings would be sparse.The Gwentian Chronicle records that "Rhodri Molwynawc" died in 750 after reigning for 30 years and "was buried at Caerleon on the Uskthe last of the race of the kings of the island of Britain who was buried there".The wide elapse of time suggests that the king whose death is reported in 814 could not have been the same person as the one whose accession is reported in 754, or else the earlier report is misdated.] (-825). [The Gwentian Chronicle records that "the kingdom of Mona and the kingdom of Dyved [were] impoverished on account of the war between Hywel Vychan and his brother Cynan, in which Hywel conquered Mona" in 810 (-[816/17]). [The Gwentian Chronicle records that "the kingdom of Mona and the kingdom of Dyved [were] impoverished on account of the war between Hywel Vychan and his brother Cynan, in which Hywel conquered Mona" in 810.While the surviving sources are consistent regarding the parentage of Ethyll, they are contradictory regarding the identity of her husband.The mid-10th century Harleian Manuscript genealogy names the ancestors of Rhodri "Mawr/the Great": "Rotri map Mermin map Etthil merch Cinnan".The Annales Cambri, said to have been compiled originally in 954, represents the oldest register of events in Wales.The version of the 12th century "Brut y Tywysogion" (Chronicle of the Princes of Wales), published with English translation in the Rolls Series in 1860 by John Williams, was incorporated into the Red Book of Hergest, a manuscript compilation of numerous 6th to 15th century literary works written in the Welsh language.
Bede records that "rex Brettonum Ceadualla" killed "Osricum" [King of Deira] in , and ruled "provinci Nordanhymbrorum" for a year before also killing "Eanfridum" [King of Bernicia] who had visited Cadwallon to sue for peace.Another view concerning the difficulty of accurately reconstructing Welsh royal genealogies is given by Bridgeman in the introduction to his History of the Princes of South Wales.He states that The chief difficulty which meets the student of Welsh medieval history is the scarcity of official deeds.It is not therefore known whether Gruffydd and Elisse were sons of Cynan King of Anglesey/Gwynedd or grandsons of Cadel King of Powys.The chronology appears to favour the former interpretation, but the uncertainty of the chronology of all these early sources is recognised.] .It appears to have been first published in the late 18th century by Edward Williams (also known as "Iolo Morganwg") who was "considered an authority on Welsh literature and folklore at the time, but was revealed as a forger in the twentieth century".