Bleddyn was born to a Powys nobleman, Cynfyn His mother, Llywelyn ap Seisyll's widow Angharad, was the daughter of KingMaredudd of Dyfed, whose realm had been lost to the Irish pretender Rhain before its conquest by Llywelyn. Gruffydd, Angharad's son by her first husband was initially dispossessed upon his father's early death. Slowly, however, he rebuilt his father's realm, annexing its successor states. Although bards and annalists had called many leaders "King of the Britons", Gruffydd was the first to rule all the free Welsh after he conquered Morgannwg in response to its invasion of Dyfed. Bleddyn may have been residing in Powys, where he married Haer ferch Cillyn, daughter of the Lord of Gest Cillyn y Blaidd Rudd.
Reign
Gruffydd's consolidation of power and alliance with Ælfgar of Mercia made him a threat to Harold Godwinson, earl of Hereford. Upon Ælfgar's death in 1060, Harold and his brother Tostig quickly invaded; the following year, they invaded again and were left in mastery of Wales after traitors among his men killed Gruffydd during a retreat. The south was restored to the Houses of Dinefwr and Morgan, but Powys and Gwynedd were given to Gruffydd's half-brothers Bleddyn and Rhiwallon. These two submitted to Harold and swore themselves vassals and allies of Edward the Confessor. Closely allied with Harold, the brothers joined the Saxon resistance to William the Conqueror following his conquest of England. In 1067, they joined the Mercian Eadric the Wild in his attack on Norman Hereford, ravaging the lands as far as the River Lugg. In 1068, they joined Earls Edwin of Mercia and Morcar of Northumbria in their attacks as well. In 1070, Gruffydd's sons challenged Bleddyn. Rhiwallon and Idwal and Maredudd died in the Battle of Mechain. Bleddyn was the king of both Gwynedd and Powys. In 1073, Robert of Rhuddlan stealthily established his forces on the banks of the RiverClwyd and attempted to ambush and capture Bleddyn. He narrowly failed, but seized valuable booty in raids further south. Bleddyn was killed in 1073 by King Rhys ab Owain of Deheubarth, having been betrayed by the lords of Ystrad Tywi. When Rhys was later defeated at the 1078 Battle of Goodwick by Bleddyn's successor, Trahaearn ap Caradog, and killed by Caradog ap Gruffydd of Gwent shortly afterwards, this was hailed as "vengeance for the blood of Bleddyn ap Cynfyn". After his death, Gwynedd was seized by Trahaearn and later recovered for the House of Aberffraw by Gruffudd ap Cynan; but in Powys, Bleddyn was the founder of a dynasty which lasted until the end of the 13th century.
Legacy
Bleddyn's legacy in the Chronicle of the Princes was that of a benevolent ruler: Bleddyn was also responsible for a revision of the Welsh law which continued in force in his dynasty's domain of Powys. Gwynedd's Venedotian Code noted that he changed the legal composition of the homestead for purposes of inheritance etc., varying its size depending on the social status of the owner. The homestead of a nobleman was 12 Welsh acres, that of a serf had 8, and that of a bondsman or slave had 4.
