(1238–1283). Prince of Gwynedd. Third son of Gruffudd ap Llywelyn, younger brother of Llywelyn ap Gruffudd (Llywelyn the Last). Intermittently in conflict with his brother and in alliance with Edward I, but in 1282 started revolt against English dominance and assumed the style Prince of Wales after his brother’s death at Cilmeri. Hanged, drawn and quartered by Edward in 1283.