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
Alys ferch Owain Glyndŵr this day in Kentchurch on the modern day England/Wales border almost exactly halfway between Abergavenny and Hereford near the River Monnow. In 1999, it was reported that they knew the precise whereabouts of Glyndŵr's secret grave. In 2006, the Owain Glyndwr Society's president Adrien Jones said: "Four years ago we visited a direct descendant of Glyndwr, a John Skidmore, at Kentchurch Court, near Abergavenny. He took us to Mornington Straddle, in Herefordshire, where one of Glyndwr's daughters, Alice, lived. Mr Skidmore told us that he (Glyndŵr) spent his last days there and eventually died there... It was a family secret