Until 1974, Glamorgan, or sometimes Glamorganshire, was an administrative county in the south of Wales, and later classed as one of the thirteen historic counties of Wales. Originally an early medieval petty kingdom of varying boundaries known in Welsh as Morgannwg, which was then invaded and taken over by the Normans as the Lordship of Glamorgan. The area that became known as Glamorgan was both a rural, pastoral area, and a conflict point between the Norman lords and the Welsh princes. It was defined by a large concentration of castles.

The Vale of Glamorgan, locally referred to as The Vale, is a county borough in the south-east of Wales. It borders Bridgend County Borough to the west, Cardiff to the east, Rhondda Cynon Taf to the north, and the Bristol Channel to the south. With an economy based largely on agriculture and chemicals, it is the southernmost unitary authority in Wales. Attractions include Barry Island Pleasure Park, the Barry Tourist Railway, Medieval wall paintings in St Cadoc's Church, Llancarfan, Porthkerry Park, St Donat's Castle, Cosmeston Lakes Country Park and Cosmeston Medieval Village. The largest town is Barry. Other towns include Penarth, Llantwit Major, and Cowbridge. There are many villages in the county borough.