In 1277 shortly after the castle had been completed Roger Mortimer and Henry de Lacy, Earl of Lincoln besieged it. It fell on 8 April 1277 because a well had not been constructed and the occupants ran out of water. Custody was firstly given to Gruffydd ap Gwenwynwyn but subsequently to Roger Mortimer along with the lands of Ceri and Cedewain. Following its fall, the castle design was modified by its new English overlords. The south gate was blocked, new buildings were set up in the courtyard, and a well was dug.