Llywelyn Farw, the Great (Welsh: Llywelyn [ɬəˈwɛlɨn vaur]), full name Llywelyn ap Iorwerth, (c. 1172 – 11 April 1240)
Prince of Gwynedd in north Wales and eventually de factoruler over most of Wales. By a combination of war and diplomacy he dominated Wales for 40 years.
During Llywelyn’s boyhood, Gwynedd was ruled by two of his uncles, who split the kingdom between them, following the death of Llywelyn’s grandfather, Owain Gwynedd.
Llywelyn had a strong claim to be the legitimate ruler and began a campaign to win power at an early age. He was sole ruler of Gwynedd by 1200 and made a treaty with King John of England.
He married King John’s daughter; Joan of Wales, Joan in 1205, and when King John arrested Gwenwynwyn ab Owain of Powys in 1208, Llywelyn took the opportunity to annex southern Powys.
In 1210, relations deteriorated, and
King John invaded Gwynedd in 1211. Llywelyn was forced to seek terms and to give up all lands east of the River Conwy, but was able to recover them the following year in alliance with the other Welsh princes.
He allied himself with the barons who forced John to sign the Magna Carta in 1215. Right after, King John died.
Llywelyn had now established himself as the leader of the independent prince of Wales, and in December 1215 led an army which included all the lesser princes. He captured the castles of Carmarthen, Kidwelly, Llanstephan, Cardigan and Swansea.
Douglas Richardson. Magna Carta Ancestry, 2nd Edition, Vol. I, pg 387.
Douglas Richardson, Kimball G. Everingham, Plantagenet ancestry: a study in colonial and medieval families. Genealogical Pub Co, 2004