The administrative county of Powys was created in 1974 as part of a local government reorganisation in England and Wales. Powys incorporated the existing counties of Montgomeryshire, Radnorshire and Breconshire (Brecknockshire). Powys's social services department took over the management of children's homes previously run by the Montgomeryshire, Radnorshire and Breconshire County Councils.

Following a further reorganisation in 1996, the county was reconstituted, with only some minor boundary changes, as a unitary authority.