Gruffydd ap Llywelyn was the Welsh first-born son of Llywelyn the Great.
Background
His mother Tangwystl probably died in childbirth. As a boy, Gruffydd was one of the hostages taken by King John of England as a pledge for his father"s continued good faith. On his father"s death in 1240, under Welsh law, he would have been entitled to consideration as his father"s successor.
Career
A clause in Magna Carta (1215) compelled his release. Llywelyn went to great lengths to strengthen Dafydd"s position, probably aware that there would be considerable Welsh support for Gruffydd against the half-English Dafydd. Following a successful invasion of the Welsh borders by King Henry III of England in 1241, Dafydd was obliged to hand over Gruffydd into the king"s custody, he was then taken to London and imprisoned in the Tower of London.
However, Gruffydd died while attempting to escape from the Tower in 1244.
He is said to have used an improvised rope made from sheets and cloths to lower himself from his window, but as he was a heavy man, the rope broke and he fell to his death. In 1248, the abbots of Strata Florida and Aberconwy arranged for the return of his body to Wales, where he was buried at Aberconwy with his father.
After his death Gruffydd"s four sons—Owain, Llywelyn, Dafydd and Rhodri—would come into their own, and after much fraternal discord, Llywelyn ended up ruling most of Wales. He also had three daughters, Gwladus, Catherine and Margred.
According to several non-contemporary Welsh genealogical tracts, the mother of Llywelyn was Rhanullt, an otherwise unknown daughter of Rǫgnvaldr Guðrøðarson, King of the Isles.
If correct, these sources could indicate that Gruffydd married a daughter of Rǫgnvaldr in about 1220. Contemporary sources, however, show that Llywelyn"s mother was Senana, an undoubted wife of Gruffydd.