born 0441; 1208
died Feb. 25, 1246, Aber, Gynedd, Wales
Welsh prince, ruler of the state of Gwynedd in northern Wales (124046).
His father, Llywelyn ap Iorwerth , had made Gwynedd the centre of Welsh power. David, the rightful heir, fought his half brother for power and imprisoned him in 1239. He was forced to cede part of his territory to Henry III of England (1241) and later went to war against Henry. The first Welsh ruler to declare himself prince of Wales, he fell ill and died while the war was in progress.