Llywelyn ap Gruffydd (d. 1282), prince of Wales (1246–82). Known as Llywelyn ‘the Last’, his ambition to create a permanent, independent Welsh principality came close to realization. The second son of Gruffydd, son of Llywelyn ab Iorwerth, he may have been designated the heir of his uncle Dafydd ap Llywelyn. After Dafydd's death (1246) and the treaty of Woodstock with Henry III (1247), Llywelyn and his elder brother Owain were restricted to Gwynedd west of the river Conwy. By 1255 Llywelyn had defeated his brothers and restored his uncle's dominion: he advanced east of the Conwy, exploited divisions in England, and raided to south Wales. Most Welsh lords regarded him as overlord (1258) and Llywelyn took the title of prince of Wales. At Pipton (1265) Simon de Montfort acknowledged his status and promised Llywelyn his daughter (though the marriage did not take place until 1278). At Montgomery (1267) Henry III conceded recognition. But in Gwynedd, Llywelyn's rule alienated churchmen and his brother Dafydd, who deserted him in 1274; there was an attempt to assassinate Llywelyn in Powys. He also misjudged Edward I in refusing to fulfil his obligations as the king's vassal. The war of 1276–7 was a disaster for Llywelyn, who was confined once more to west Gwynedd by the treaty of Aberconwy (1277); he kept his title but only five Welsh barons were acknowledged to be his vassals. The uneasy peace was shattered by Dafydd's impulsive assault on Hawarden (1282) and, in the renewed struggle with Edward, Llywelyn was killed near Builth on 11 December.

Ralph Alan Griffiths

Llywelyn ap Gruffydd (1225–82) ( Llywelyn the Last) Prince of Wales. Allied with the rebellious English barons, he gained control of as much territory as his grandfather, Llywelyn ap Iorwerth. He was recognized as Prince of Wales by the Treaty of Montgomery (1267). With the accession of Edward I, he renewed his rebellion in 1282 and was killed in battle.