Glamorganshire is one of the historic Welsh counties, although commonly known simply as Glamorgan as there is no county town of that name to confuse the issue. It was created by the Acts of Union 1536-1543, in the process known as the Shiring of Wales from the fusion of the former Marcher lordships of Gower and Glamorgan. The name Glamorgan itself being an English corruption of the Welsh Gwlad Morgan or 'Morgan's country' an alternative name for the old Welsh kingdom of Morgannwg; in Welsh the county is knowns as Sir Forgannwg or simply just Morgannwg.
Glamorganshire is located on the south-east coast of Wales with its southern borders facing the Bristol Channel; to the north lies Brecknockshire, to the east Monmouthshire and to the west Carmarthenshire. The county includes the cities of Cardiff and Swansea as well as the towns of Aberdare, Barry, Bridgend, Caerphilly, Cowbridge, Maesteg, Merthyr Tydfil, Mountain Ash, Neath, Penarth, Pontypridd, Porthcawl and Port Talbot.
The north of the county is mountainous, featuring a number of deep narrow valleys, created by a series of rivers such as the Lougher (which marks the border with Carmarthenshire in the west), the Tawe, the Ogmore, the Dulais, the Taff, and the Rhymney which defines the eastern border with Monmouthshire. In the south of the county is the lowland area known as the Vale of Glamorgan that stretches from Cardiff in the east, almost as far as Swansea in the west; beyond Swansea, lies the peninsula of Gower, which has been designated an Area of Outstanding Natural Beauty.
Glamorganshire was essentially as rural and agricultural as the rest of Wales until the eighteenth and particularly nineteenth century, when it was transformed as a result of the development of the iron and later the coal industry. Merthyr Tydfil in the north of the county becoming arguably the world's first industrial town, and the northern valleys became one long series of coal mines and pit villages squeezed onto the hillsides. There was a similar growth in the coastal towns of Cardiff and Swansea which all became ports feeding off the coal trade.
There was a significant increase in population, fed initially by internal migration within Wales, but was later by external migration from outside Wales, which led to the eventual anglicisation of the county. Glamorganshire therefore became and remains to this day the most populous as well as one of the most English of the Welsh counties. With a population of around 1.25m, just over 40% of the total inhabitants of Wales live in Glamorganshire.
The coal industry has now all but disappeared and there are now more call centres than coal mines and the dock facilities have been converted into marinas. The old industrial valleys remain somewhat economically subdued but the south of the county is far more prosporous, lying as it does at the western extremity of the M4 corridor. Cardiff in particular benefits from being the designated capital city of Wales and is the location for the Welsh Assembly as well as the adminstrative functions of the Welsh Office.
Glamorganshire ceased to exist as an administrative entity in 1974 when it was divided into three new counties under the names of South, West and Mid Glamorgan. That set up lasted until 1996 when they were abolished and replaced with the following unitary councils
Which to together make up the old historic county of Glamorganshire.
It also has the distinction of being the only Welsh county with its own County Cricket team, which has even, on the odd occaision, been known to have won something.
Based on information taken from the National Gazetteer of Wales at www.gazetteer-wales.co.uk as well as information from GENUKI Administrative Areas of Wales at www.genuki.org.uk/big/Regions/Wales.html plus whatever else I could remember.