The site known today as "Mathrafal Castle" is a roughly 100 m square rectangular compound defended by ditches. Little remains of the original walls. This structure probably dates from around the 9th Century and replaces an earlier hill fort, about 1 km away, which probably dates from around 656 at the time of the fall of the neighbouring Kingdom of Pengwern, or perhaps as early as 520 when the capital of Powys was moved from the old Roman town of Viroconium Cornoviorum (Wroxeter). Prince Gwenwynwyn ab Owain of Powys moved his capital from Mathrafal to Welshpool (Y Trallwng) after it was destroyed during warfare between Powys and Gwynedd in 1212.
- John Davies, History of Wales, Penguin Books, 1990, 1993.