Montgomery Castle (Welsh: Castell Trefaldwyn) is a stone built castle looking over the town of Montgomery in Powys, Mid Wales. It is one of many Norman castles on the border between Wales and England. Its strategic importance in the Welsh Marches meant it was destroyed and rebuilt a number of times until the early 14th century, when the area was largely pacified. During the First English Civil War, it was the site of the largest battle in Wales on 17 September 1644; the walls were demolished after the Second English Civil War in 1649 to prevent the castle being used again.