Nearly the whole of Radnorshire; east Flint, including the neighbouring districts of Ruabon and Wrexham in Denbighshire; east Brecknock; east Montgomery; south Pembroke, with the adjoining district of Laugharne in Carmarthenshire; and the districts of Gower, Vale of Glamorgan and Cardiff in south Glamorgan.
The commercial greatness of Cardiff is due to the vast coal and iron deposits of the country drained by the Taff and Rhymney, between whose outlets the town is situated.
The Bute trustees in 1885 acquired the Glamorgan canal and its dock, and in the following year obtained an act for vesting their various docks and the canal in a company now known as the Cardiff Railway Company.
The Barry line from Barry dock joins the Great Western and Taff Vale railways at Cardiff, and the Cardiff Railway Company (which owns all the docks) has a line from Pontypridd via Llanishen to the docks.
The Glamorganshire canal, opened in 1794, runs from Cardiff to Merthyr Tydfil, with a branch to Aberdare.
Each chief valley has a railway connecting a string of mining villages, and converging seaward to the busy ports of Newport, Cardiff and Barry (a town created on a sandy island by the excavation of a great dock to form an outlet for the mines).
Copper, tin and lead works are everywhere numerous in the busy valleys of north Glamorgan and in the neighbourhoods of Swansea, Neath, Cardiff and Llanelly.
The great sessions for the county were during their whole existence from 1542 to 1830 held at Cardiff, but the assizes (which replaced them) have since then been held at Swansea and Cardiff alternately, as also are the quarter sessions for Glamorgan.
On the conquest of the district by the Normans under Fitz Hamon, Cardiff became the caput of the seigniory of Glamorgan, and the castle the residence of its lords.
Indeed, experiments have been made in this direction near Cardiff in South Wales.