Out of the power struggle in Gwynedd eventually arose one of the greatest of Welsh leaders, Llywelyn ab Iorwerth, also known as Llywelyn "Fawr" (the Great), who was sole ruler of Gwynedd by 1200 and by his death in 1240 was effectively ruler of much of Wales. Llywelyn made his 'capital' and headquarters at Abergwyngregyn on the north coast, overlooking the Menai Strait. His son Dafydd ap Llywelyn followed him as ruler of Gwynedd, but king Henry III of England would not allow him to inherit his father's position elsewhere in Wales. War broke out in 1241 and then again in 1245, and the issue was still in the balance when Dafydd died suddenly at Abergwyngregyn, without leaving an heir in early 1246. Llywelyn the Great's other son, Gruffudd had been killed trying to escape from the Tower of London in 1244. Gruffudd had left four sons, and a period of internal conflict between three of these ended in the rise to power of Llywelyn ap Gruffudd (also known as "Llywelyn Ein Llyw Olaf"; "Llywelyn, Our Last Leader"). The Treaty of Montgomery in 1267 confirmed Llywelyn in control, directly or indirectly, over a large part of Wales. However, Llywelyn's claims in Wales conflicted with Edward I of England, and war followed in 1277. Llywelyn was obliged to seek terms, and the Treaty of Aberconwy greatly restricted his authority. War broke out again when Llywelyn's brother Dafydd ap Gruffudd attacked Hawarden Castle on Palm Sunday 1282. On 11 December 1282, Llywelyn was lured into a meeting in Builth Wells castle with unknown Marchers, where he was killed and his army subsequently destroyed. His brother Dafydd ap Gruffudd continued an increasingly forlorn resistance. He was captured in June 1283 and was hanged, drawn and quartered at Shrewsbury. In effect Wales became England's first colony until it was finally annexed through the Laws in Wales Acts 1535-1542.