[1] Although the cavalry link remained part of its defining character, as early as the Battle of Waterloo the RHA was sometimes deployed more along the lines of conventional field artillery, fighting from comparatively fixed positions.

Britain remained in conflict with France for almost 22 years, during which time significant progress was achieved in artillery development.

Another development was the formation of a headquarters staff providing a channel between the regiment and the Board of Ordnance.

By 1806, eleven troops had been formed, with ten companies of the Royal Irish Artillery incorporated, as the Seventh Battalion, after the union with Ireland in 1801.

Included in the establishment were 45 drivers and 187 horses, making it the first self-contained fighting unit of artillery.

[5][6] The regiment wore light cavalry uniforms of blue with gold lace and red facings.

[9] At the outbreak of World War I the regular RHA comprised twenty-five batteries, eleven of those serving in India with the Indian Army.

At the onset of World War II, recruits were instructed that "the role of the Royal Artilleryman is, as it has ever been, to fight his gun, forgetful of self, to the last round in support of other arms.

"[3]: p 107 The following are current units of the Royal Horse Artillery:[13][14] The Royal Horse Artillery provided the Queen's Guard on three occasions: The King's Troop provides the King's Life Guard in Whitehall for three weeks in August each year while the Household Cavalry Mounted Regiment goes away for summer training.