Montgomeryshire (Welsh: Sir Drefaldwyn meaning "the Shire of Baldwin's town") was one of the thirteen historic counties of Wales.

Ultimately this led them to convert their territory into a marcher lordship, via surrender and regrant, as a way to strengthen their position; the ruling princes of Powys Wenwynwyn became the Lords of Powys, feudally bound to the English king, and able to fully rely on English backing, but otherwise independent.

The prince took an English-style surname - Owen de-la Pole - after his capital city, Pool (now Welshpool).

Montgomeryshire was thus ultimately formed from the cantrefi of Powys Wenwynwyn:[2] In addition, for practical reasons, Montgomeryshire gained the commote of Ceri, which had formed a northwards spur of the less organised region Between Wye and Severn; most of the rest of the latter region became Radnorshire.

When, in subsequent centuries, the concept of Wales was once again officially distinguished from England, all of these counties were deemed Welsh, except for Shropshire.

[3][4] Montgomeryshire County Council held its first formal meeting on 1 April 1889 at the Public Rooms (also known as the Flannel Exchange) in Newtown.

[10] Further local government reform in 1996 abolished district councils in Wales, making Powys a unitary authority.

Montgomeryshire was crossed from East to West by the Cambrian Line, a mainline passenger railway which runs between Shrewsbury and Aberystwyth as well as Pwllheli with stations at Welshpool, Newtown, Caersws and Machynlleth.