In 1282 the Welsh, led by Dafydd, brother of the last prince of Wales, Llewelyn ap Grufydd, revolted against the English in northeast Wales. Edward responded with a further invasion, slaying Llewelyn at the battle of Irfon Bridge on the 11th December 1282. Llewelyn's brother Dafydd continued the Welsh resistance but he was eventually betrayed to Edward in June 1283 and executed. Edward ordered the building of further castles at Conwy, Caernarfon and Harlech.
Editors. "Welsh revolt". The Literary Encyclopedia. First published 28 March 2013
[http://www.litencyc.com/php/stopics.php?rec=true&UID=19344, accessed 28 October 2016.]