Dafydd was a prince of
Gwynedd, the third of four sons of
Gruffudd ap Llywelyn and his wife,
Senana, and thus grandson of
Llywelyn Fawr. In 1241, he was handed over to
Henry III of England as a hostage with his younger brother,
Rhodri, as part of an agreement to secure the release of his father, Gruffudd, who had been imprisoned by his half brother,
Dafydd ap Llywelyn. His brother,
Owain, made him captain of his household troops when Dafydd came of age, and in 1252 Owain invested him as lord of the
commote of Cymydmaen, at the western end of the
Llŷn Peninsula. In 1253, he was called upon to
pay homage to King
Henry III of England, where he received an offer of support from Henry, should he secure himself claims to a greater portion of the territory of Gwynedd. This, however, was opposed by his brother
Llywelyn In 1255, he joined his brother, Owain, in a challenge to their brother, Llywelyn, but Llywelyn defeated them at the
Battle of Bryn Derwin. Dafydd and Owain were imprisoned, but Llywelyn released Dafydd the following year and restored him to favour, bestowing on him landholdings in
Perfeddwlad, an area recently captured from Henry. Dafydd thus acknowledged Llywelyn's right to bestow these lands, aligning the interests of the two brothers. Dafydd served his brother loyally until, in 1263, secret negotiations with Henry's son, Edward, persuaded Dafydd to join Henry in an attack on his brother. The following year, Henry found himself under siege from a group of his rebellious barons, and Llywelyn used the situation to assert his status as Prince of Wales in 1267. Henry acknowledged him as Prince of Wales. Dafydd was again restored to Llywelyn's favour, but in 1274, he conspired with
Gruffudd ap Gwenwynwyn to kill Llywelyn. Llywelyn was alerted to the plot and called Dafydd to answer charges of treason, but he fled to the court of
Edward I, who had succeeded Henry in 1272. In 1277, following the
Treaty of Aberconwy, Dafydd was reconciled, finally, with his brother. Dafydd ap Gruffudd married (sometime after 1265)
Lady Elizabeth Ferrers, daughter of
William de Ferrers, 5th Earl of Derby, and the widow of William Marshal, 2nd Baron Marshal (not the Earl of Pembroke). Through the marriage, Dafydd came into possession of the manor of
Folesham,
Norfolk. He exchanged Folesham with John Marshal for the manor of
Norton, Northamptonshire. In September 1278, he accepted a grant for life from Edward l, King of England, of the manor of
Frodsham, near
Chester. == Struggle for Wales ==