known as Llywelyn the Great
died April 11, 1240, Aberconway, Gwynedd, Wales
Welsh prince.
The grandson of a powerful Welsh prince, he was exiled as a child from Gwynedd in northern Wales but returned in 1194 and deposed his uncle, gaining control of most of northern Wales by 1202. Though Llywelyn married King John 's daughter, the English king invaded Wales when Llywelyn's authority reached too far (1211). Llywelyn soon recovered his lands and allied with John's baronial opponents. Henry III acknowledged his rule in most of Wales (1218), but by 1223 Llywelyn was forced to withdraw to the north.