Anarawd and his immediate heirs made the village of Aberffraw on Anglesey their early principal family seat. In the 10th century, Rhodri the Great had inherited Gwynedd from his father and Powys from his mother, and he added Seisyllwg by a dynastic marriage to Angharad of Seisyllwg. Rhodri's influence in the rest of Wales was significant, and he left a lasting legacy.
Power base
The family were able to assert their influence within Gwynedd, their traditional sphere of influence, but by the 11th century they were ousted from Powys and Deheubarth by a series of strong rulers from the House of Dinefwr in Deheubarth, their dynastically junior cousins. The Dinefwr family were descended from the second son of Rhodri the Great. However, Gruffudd ap Cynan Aberffraw was able to recover his heritage and position as Prince of Gwynedd from Norman invaders by 1100. Owain Gwynedd, Gruffudd's son, defeatedKing Henry II of England and the vast Angevin host in 1157 and 1166, which led to Owain being proclaimed as Princeps Wallensium, the Prince of the Welsh, by other Welsh rulers. This proclamation reasserted and updated the Aberffraw claims to be the principal royal family of Wales, as senior line descendants of Rhodri the Great. This position was further reaffirmed in the biography The History of Gruffydd ap Cynan. Written in Latin, the biography was intended for an audience outside Wales. The significance of this claim was that the Aberffraw family owed nothing to the English king for their position in Wales, and that they held authority in Wales "by absolute right through descent", wrote historian John Davies. By 1216 Llywelyn the Great had received the fealty and homage of the Dinefwr rulers of Deheubarth at the Council of Aberdyfi. With homage and fealty paid by other Welsh lords to Llywelyn at the Council of Aberdyfi, Llywelyn the Great became the de facto first "Prince of Wales" in the modern sense, though it was his son Dafydd ap Llywelyn who was the first to adopt that title. However, the 1282 Conquest of Wales by Edward I greatly reduced the influence of the family. King Edward I of England forced the remaining members of the family to surrender their claim to the title of Prince of Wales under the Statute of Rhuddlan in 1284, which also abolished the independent Welsh peerage. The Aberffraw family members closest to Llywelyn II were imprisoned for life by Edward, while the more distant Aberffraw members went into deep hiding and fell into obscurity. Other members of the family did lay claim to their heritage; they included Owain Lawgoch in the 14th century.
Succession
Royal succession within the House of Aberffraw was a complex matter due to the unique character of Welsh law. According to Hurbert Lewis, though not explicitly codified as such, the edling, or heir apparent, was by convention, custom, and practice the eldest son of the lord or Prince and was entitled to inherit the position and title as "head of the family" from the father. This was effectively primogeniture with local variations. However, all sons were provided for out of the lands of the father, and in certain circumstances so too were daughters. Men could also claim royal title through the maternal patrimony of their mother's line in certain circumstances. The female line of the dynasty was also considered to remain royal, as marriage was an important means of strengthening individual claims to the various kingdoms of Wales and uniting various royal families to that of Aberffraw, or reuniting factions after dynastic civil wars. This meant that the female line was considered as a legitimate path of royal descent within the House of Aberffraw, with the claims of royal women to titles usually transferring to their sons. Members of the House of Aberffraw would include Idwal Foel, Iago ab Idwal, Cynan ab Iago, Gruffudd ap Cynan, Owain Gwynedd, Gwenllian ferch Gruffydd, Llywelyn the Great, Llywelyn ap Gruffudd, and Owain Lawgoch. Several later Welsh families, including the Wynn family of Gwydir and the Anwyl of Tywyn family, would claim to be heirs of the dynasty.
History
Aberffraw senior line
Gruffudd ap Cynan, Prince of Gwynedd
* Owain Gwynedd , Prince of the Welsh, Prince of Gwynedd = Cristina ferch Gronw ap Owain ap Edwin
**Hywel ab Owain Gwynedd Prince of Gwynedd 1170, succeeding as his father's chosen heir. Died 1170 in battle at , against his brother Dafydd. The Chronicle of the Princes records the following entry in the year 1170: One thousand one hundred and seventy was the year of Christ when Dafydd ab Owain slew Hywel ab Owain. See in genealogical tables in J.E. Lloyd's History of Wales: The Line of Gwynedd.
***Caswallon ap Hywel . Caswallon has proven direct male ancestors who exist into the modern day and thereby represent the senior surviving male line of Owain Gwynedd – the genealogy of one family was recorded by Peter Gwynn-Jones, late Garter King of Arms, at The College of Arms.
**Iorwerth ab Owain ,
*** Llywelyn ab Iorwerth , de facto Prince of Wales, Prince of Gwynedd and Powys, Prince of Aberffraw and Lord of Snowdon. The last of the Llywelyn line died out with the death of Owain Lawgoch in 1378
