The Royal Artillery (and also of the Royal Engineers, Royal Sappers and Miners, the Commissariat Department, and various barracks, ordnance stores, and transport departments) was transferred to the British Army when the Board of Ordnance was abolished in 1855 (the administrative branches of the Board were absorbed by the War Office) and the War Office School of Gunnery established in Shoeburyness in 1859. When the British East India Company was dissolved in 1862, its artillery function was absorbed by the Royal Artillery, giving it a total strength of 29 horse batteries, 73 field batteries and 88 heavy batteries.^[5] Military expenditure estimates for 1872 list the regimental strength as a total of 34,943 men and officers, including those in India.^[25]

Although the Militia and the Volunteer Force remained separate forces, during the latter half of the Nineteenth Century they were re-organised through a succession of reforms, and increasingly integrated with the British Army. In 1882, the Militia Artillery units lost their individual identities, becoming numbered brigades organised within Royal Artillery territorial divisions (two brigades of horse artillery, four brigades of field artillery and eleven territorial divisions of garrison artillery). In 1889 the number of divisions was reduced to three, and the Militia Artillery brigades were renamed again, mostly regaining some variation of their original territorial names.

Post 1881, militia artillery officers wore for a brief time five button serge foreign service frocks with ball buttons and silver lace. Post 1890, officers transitioned to pocketed examples, again with ball buttons but the frocks varying from pure blue serge to other examples with scarlet facings.