Criccieth Castle a distant relation of Llywelyn ap Gruffudd, began an uprising against English rule that spread quickly through Wales. Several English-held towns were razed and Criccieth (along with Harlech Castle and Aberystwyth Castle) were besieged that winter. Its residents survived until spring when the castle was resupplied. In the 14th century the castle had a notable Welsh constable called Hywel ap Gruffydd, known as Howell the Axe, who fought for Edward III at the Battle of Poitiers in 1356. The castle was used as a prison until 1404 when Welsh forces captured the castle during the rebellion of Owain Glyndŵr. The
Owain Glyndŵr the French. The result was a formal treaty that promised French aid to Owain and the Welsh. The immediate effect seems to have been that joint Welsh and Franco-Breton forces attacked and laid siege to Kidwelly Castle. The Welsh could also count on semi-official fraternal aid from their fellow Celts in the then independent Brittany and Scotland. Scots and French privateers were operating around Wales throughout Owain's war. Scottish ships had raided English settlements on the Llŷn Peninsula in 1400 and 1401. In 1403, a Breton squadron defeated the English in the Channel and devastated Jersey, Guernsey and Plymouth, while