Welshpool is said to have developed shortly after two churches were founded in the area by the brothers, SS. Cynfelin and Llewelyn, in the sixth century (NPRN 96014). Even earlier occupation is suggested by the Roman burial discovered in the Smithfield area, however no other traces have been discovered. Domen Gastell (306957), the defensive motte and bailey, which will have been key to the town's growth, first appears in the historical record in 1196; its exact date of building remains unknown. By the late thirteenth century Domen Gastell was overshadowed by Powis Castle (29858) to the west of the town.
Welshpool received borough status around the 1240s, and markets are recorded in the town by 1252, the principle trades being malt and textiles. In 1400 the town was burned early in the rebellion of Owain Glyndwr, but recovered sufficiently by 1411 to be the home of the famed writer, Adam of Usk. By the 1530s Leland referred to Welshpool as the `best market in Powys? (NPRN 408627)
During the eighteenth century the flannel industry allowed the town to develop significantly, aided by the arrival of the Montgomeryshire Canal (nprn 34605) in 1796, and the Cambrian Railways (Station: nprn 80506) in 1862. Today the town is famous for the Smithfield Livestock Market, the largest in Europe.
K Steele, RCAHMW, 6 January 2009.