Builth's unfinished state did not prevent it from working as a fortress. Forces in Madog ap Llywelyn's revolt besieged the castle in 1294 but failed to take it. Edward I gave Builth to his son Edward in 1301 to help organise and support the territory. Roger Mortimer served as castellan from 1310 to 1315. The castle continued to carry defensive and administrative value despite the limited investment in its fabric.
Notable Point · 4:25-4:50
The unfinished castle proves defensible
Madog ap Llywelyn's revolt tests Builth in 1294, but the unfinished castle holds and remains useful enough for a royal grant and Roger Mortimer's castellanship.