Until 1974, Brecknockshire, also formerly known as the County of Brecknock, Breconshire, or the County of Brecon, was an administrative county in the south of Wales, later classed as one of the thirteen historic counties of Wales. Named after its county town of Brecon, the county was mountainous and primarily rural.

Brecon, archaically known as Brecknock, is a market town in Powys, mid Wales. In 1841, it had a population of 5,701. The population in 2001 was 7,901, increasing to 8,250 at the 2011 census. Historically it was the county town of Brecknockshire (Breconshire); although its role as such was eclipsed with the formation of the County of Powys, it remains an important local centre. Brecon is the third-largest town in Powys, after Newtown and Ystradgynlais. It lies north of the Brecon Beacons mountain range, but is just within the Brecon Beacons National Park.