In 1132, King Madog of Powys brought an order of Benedictine monks to Teigengl, a cantref in Northeast Wales. They settled first at Hen Blas, a former llys of the Princes of Gwynedd, before moving in 1157 to the current location of Basingwerk Abbey.
Surviving ruins, which are extensive, include the 12th century chapter house, which is the oldest part of the abbey, a dormitory, the dining hall with its own through to the kitchen, and the outline of the cloister. The church itself is also a significant ruin.
The area around Basingwerk was fought over by the kings of Gwynedd and Powys for decades, if not centuries. Particularly after the arrival of the Normans, King Madog of Powys often allied with Earl Ranulf of Chester against King Owain Gwynedd in their contest for control of northeastern Wales.
By 1147 the monks had joined the Cistercian order under the patronage of Earl Ranulf of Chester. Then, in 1157, King Owain camped at Hen Blas before his victory at the Battle of Ewloe, where he defeated a combined force of King Henry II of England, Madog of Powys, and his own brother, Cadwaladr. Despite the victory, Owain then retreated to St. Asaph, ceding control of the cantref to the Earl of Chester. He then moved the monks to Basingwerk’s current location on the Dee Estuary.
The abbey was once again under Welsh patronage in the 13th century, as both Llywelyn Fawr and his grandson Llywelyn ap Gruffydd extended their reach all the way to the Dee. After the Reformation, the abbey was abandoned and its assets sold.