Their role was to man coastal defences and fortifications, relieving the Royal Artillery (RA) for active service.

[1][2] In 1854 the Lord Lieutenant of Glamorgan was instructed to raise a corps of militia artillery to man the fortifications proposed for the Glamorganshire coast, particularly Swansea Bay.

[5][6][7][8][9] However, recruitment from the coal and iron districts of Glamorgan proceeded slowly, although the ballot was not resorted to.

It was reported[10] that the unit would be employed exclusively in defending the coast of Glamorgan – under the 1852 Act the Militia were liable for service anywhere in the United Kingdom – which together with the slowness of recruiting and lack of training may explain why it was never embodied during the Crimean War or the Indian Mutiny.

A proposal to mount a heavy battery for the RGAM on the salient angle of Swansea Pier was abandoned when it was found that the structure would not support its weight.

In the late 1870s at least two of the 68-pdrs were replaced by 80-pdr rifled muzzle-loaders[a] on traversing slide carriages, but financial stringency prevented any further modernisation and the battery's armament remained unchanged to the end of the 19th Century.

After another reorganisation in 1889 the official title was altered to Glamorgan Artillery (Western Division) RA.

There were moves to reform the Auxiliary Forces (Militia, Yeomanry and Volunteers) to take their place in the six Army Corps proposed by St John Brodrick as Secretary of State for War.

[9][14][15] Under the sweeping Haldane Reforms of 1908, the Militia was replaced by the Special Reserve, a semi-professional force whose role was to provide reinforcement drafts for Regular units serving overseas in wartime.