Knighton is unique in being the only town to sit astride Offa's Dyke (NPRN 276071-4), the earthwork defence constructed by the King of Mercia in the late eighth century to divide England and Wales. It is also notable as the starting point of Glyndwr's Way, following the route of the Welsh leader's significant battles. The town developed around Knighton Castle (NPRN 300070), originally a motte and bailey believed to have been constructed in the late eleventh century by Hugh L?asne. A second castle, Bryn y Castell (NPRN 300071), was constructed nearby after Knighton Castle was seized by the Welsh in 1215. The town has, for much of its history, has been both English and Welsh, with the town crossing the border, until the 1535 Acts of Union confirmed its status as Welsh.
In 1230 the town was granted a charter permitting a weekly market and annual fair, and this continues to this day, despite interruptions such as Owain Glyndwr's burning of the town and castle in 1402. In the fifteenth century Knighton enjoyed a prosperous wool trade, but there was little industry in the town, which now enjoys a tourist trade encouraged by the presence of the Offa's Dyke Centre and the designated National Trail, starting at the town's Clock Tower (NPRN 32969).

K Steele, RCAHMW, 16 January 2009