Dafydd ap Gruffydd was the younger brother of Llywelyn ap Gruffydd, the Prince of Wales who ruled portions of Wales, to a greater or lesser degree, since the death of his uncle (also named Dafydd) in 1246. The younger Dafydd was born in 1238, thirteen years after Llywelyn. This Dafydd spent the majority of his life in England, to which his family was forced to come when his father was imprisoned at the Tower of London by King Henry. Llywelyn, 16 at the time and a man, had refused to leave Wales with the rest of his family, and thus was on the spot, so to speak, when his uncle Dafydd died.
At that point, Dafydd ap Gruffydd was only 8 years old, and in no sense prepared to put forth a claim to his patrimony. That occurred for the first time in 1255, when he conspired with his brother, Owain Goch, to force Llywelyn to relinquish some of his lands to Dafydd. They were defeated in the Battle of Bryn Derwin. Llywelyn accepted Dafydd back into his favor a year later, only to have Dafydd betray him again in 1263, and again in 1274 when he attempted to assassinate Llywelyn.
To say that Dafydd had a problematic relationship with Llywelyn is an understatement. Llywelyn kept Owain Goch imprisoned for the rest of his life, but he released Dafydd after Bryn Derwin and gave him lands, ultimately bowing to his younger brother’s rightful claim. At the time, Llywelyn perceived Owain, the elder brother, as the greater threat.
From Brynne Haug: “Dafydd’s choice to turn to Edward in 1263 and again in 1274 was self-serving in that he believed his chances better with the king than with Llywelyn. Llywelyn had little choice but to accept Dafydd back when he changed his mind: in 1267 Edward I stipulated it in the Treaty of Mongomery, and it was again a condition in 1277.” What must have been most aggravating to Llywelyn was that Dafydd was one of the impetuses for ALL of the wars against England that peppered his reign: in 1267, in 1277, both times when he fought against Llywelyn on the side of the English, and in 1282, when he forced Llywelyn to throw his weight behind Dafydd himself after he launched an attack on Edward’s castles in Wales.
Whatever his motives, Dafydd did stay true to Wales after Llywelyn’s death. In June 1283, English soldiers captured Dafydd, took him to Shrewsbury, and, in October, executed him. He was hung, drawn, and quartered, and his head displayed in the tower of London alongside Llywelyn’s.
J. Beverly Smith, Llywelyn ap Gruffydd: The Prince of Wales.
Brynne Haug, Captive Cymru: Llywelyn and Gwynedd in the Wars of King Edward.
Peniarth MS 20, The Chronicle of the Princes