On the death of King Henry III in 1272, his son Edward I became the king and was able to express his dislike of the Celts, particularly Llewelyn ap Gruffydd (1223-1282), the last prince of Wales who had been forced to sign the Treaty of Woodstock in 1247. In this treaty he accepted English rule of north Wales from Chester to the River Conwy and limited his own terrain to west Gwynned. There followed some thirty years of shifting alliances between Welsh and English barons which culminated in 1277 with Edward declaring Llewelyn a rebel, invading with a formidable army and re-establishing English authority along the north Wales coast. Edward then ordered the building of impressive castles at Flint, Rhuddlan, Builth and Aberystwyth to …
Editors. "Edward I invades Wales". The Literary Encyclopedia. First published 28 March 2013; last revised .
[http://www.litencyc.com/php/stopics.php?rec=true&UID=19343, accessed 23 May 2015.]