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 1412, Owain led one of the final successful raiding parties with his most faithful soldiers and cut through the King's men; and in an ambush in Brecon he captured, and later ransomed, a leading Welsh supporter of King Henry's, Dafydd Gam ("Crooked David"). This was the last time that Owain was seen alive by his enemies. As late as 1414, there were rumours that the Herefordshire-based Lollard leader Sir John Oldcastle was communicating with Owain, and reinforcements were sent to the major castles in the north and south. But by then things were changing. Henry IV died in 1413 and