In 1294, following the war of 1277 and revolt of 1282, there was a further Welsh rebellion against English oppression. This was rapidly defeated and Beaumaris Castle was built to secure the Isle of Anglesey.
Editors. "Welsh revolt". The Literary Encyclopedia. First published 28 March 2013
[http://www.litencyc.com/php/stopics.php?rec=true&UID=19345, accessed 10 March 2014.]