MONTGOMERY ( Tre' Faldwyn)  , a municipal and parliamentary borough, market town, and the county town of Montgomery-shire, Wales, situated on a wooded hill near the east bank of the Severn, 7 M . S. of Welshpool (Cambrian railway) . Pop . (1901), 1034 . The principal feature of the town is the ruined castle . Not far off are the traces of an extensive British fort, and, about a mile east, the line of Offa's Dyke, forming the Shropshire boundary . The borough was incorporated by Henry III., when the castle was enlarged, and was the scene of frequent contests between that king and Llewelyn the Great . In the 14th century the castle was held by the Mortimers, from whom it passed to the Yorkists . The Crown gave it, in the 15th century, to the Herberts of Cherbury, one of whom, in 1644, surrendered it to the Parliamentarians, who dismantled it .