In addition to the Second Rocket Troop, D Troop also was reduced in 1816; and, in spite of strong remonstrances,—among others, from the late Sir Robert Gardiner, then Captain of E Troop,—the titles of all the troops below D were changed, E, F, G, H, and I becoming respectively D, E, F, G, and H. The injury and inconvenience caused by this alteration of nomenclature have proved very great. K, L and M Troops were reduced at the same time, but being the juniors, their reduction did not affect the lettering of the others.
In January, 1819, B and G Troops were reduced; but on this occasion no alteration was made in the designations of the other troops. B Troop was reformed on the 1st 1855, as a reserve half-troop, under a Second Captain, and was augmented to a full troop in the following year. G Troop was reformed at Woolwich on the 1st December, 1857, and also K Troop on the same day.
On the 1st July, 1859, with the introduction of the Brigade System, came an alteration in the titles of the troops, which were now designated as Batteries of the Horse Brigade. In 1862, on account of the amalgamation with the East India Company's Artillery, the old Royal Horse Artillery became the First Horse Brigade of the Royal Artillery; and in 1864, to enable the Indian reliefs to be carried on without sending the whole of the old Horse Artillery abroad at one time, the First Horse Brigade was divided into A and B Brigades of the Royal Horse Artillery.
At the date of this work (1872) the following list shows the present designations of the old troops, as they stood in 1859:—
| A Troop is now called | A Battery A Brigade |
| B Troop is now called | B Battery A Brigade |
| C Troop is now called | C Battery A Brigade |
| D Troop is now called | A Battery B Brigade |
| E Troop is now called | B Battery B Brigade |
| F Troop is now called | C Battery B Brigade |
| G Troop is now called | D Battery A Brigade |
| H Troop is now called | D Battery B Brigade |
| I Troop is now called | E Battery B Brigade |
| K Troop is now called | E Battery A Brigade |
The military operations in which these batteries have been severally engaged, and their succession of Captains, will now be given. The more detailed history given of A Troop—"The Chestnut Troop"—is attributable to the labour taken by its Captain, the late Sir Hew Ross, who completed the records of its active service with his own hand.
A TROOP, R.H.A.,
Now "A" BATTERY, A BRIGADE.
| Battles, Sieges, and other Military operations in which this Company has been engaged. | |
| 1798 | The affairs of Ross, Wexford, and Vinegar Hill, June. |
| 1799 | Egmont-op-Zee on 19th September. |
| 1799 | Near Alkmaar on 6th October. |
| 1809 | Retreat from Talavera on 3rd August. |
| 1810 | Action in front of Almeida in the Duas Casas on 20th July. |
| 1810 | Action on the Coa on 24th July. |
| 1810 | Battle of Busaco on 27th September. |
| 1811 | Action at Pombal on 11th March. |
| 1811 | Action on the Plain in front of Redinha on 12th March. |
| 1811 | Action in front of Cazal Nova on 13th March. |
| 1811 | Action at Foz d'Arouce on the Ceira on 15th March. |
| 1811 | Action at Sabugal on the Coa on 3rd April. |
| 1811 | Battle of Fuentes d'Onore on 5th May. |
| 1811 | Action in front of Mortagoa on the right bank of the Agueda on 10th July. |
| 1812 | Siege of Ciudad Rodrigo, January. |
| 1812 | Siege of Badajoz, April. |
| 1812 | Affair in front of Salamanca on 16th June. |
| 1812 | Action at Castrejou on the Guavena on 18th July. |
| 1812 | Battle of Salamanca on 21st July. |
| 1812 | Action on the Huebra on 15th November. |
| 1813 | Affair in front of Salamanca in the advance on Vittoria on 22nd May. |
| 1813 | Affair near Burgos in the advance on Vittoria on 12th June. |
| 1813 | Affair at St. Millan and Osmo on 18th June. |
| 1813 | Battle of Vittoria on 21st June. |
| 1813 | Daily affairs with the French between 22nd and 27th June. |
| 1813 | Action before Pampeluna at daybreak when the French lost the only two guns they brought from Vittoria, on 25th June. |
| 1813 | Actions in the Pyrenees on 26th, 27th and 28th July. |
| 1813 | Heights of San Marcial near Yrun on 31st August. |
| 1813 | Attack on La Rhune Mountain and its chain of heights in the Pyrenees on 10th November. |
| 1813 | Passage of the Nivelle on 10th November. |
| 1813 | Passage of the Nive on 9th December. |
| 1813 | Battle of St. Pierre de Grube, near Bayonne. |
| 1814 | Passage of the Gave d'Oléron. |
| 1814 | Battle of Orthes on 27th February. |
| 1814 | Action in front of La Reole on the right of the Gavonne on 14th March. |
| 1814 | Affairs in front of La Reole, almost daily, between 14th March and 14th April.[[52]] |
| 1815 | Battle of Waterloo, June 17th and 18th, and capture of Paris. |
| 1855 | Siege of Sebastopol. |
| List of Captains who have successively commanded the Company, as far back as can be traced, down to introduction of Brigade System, in 1859. | |
| 1793 | Captain R. Lawson. |
| 1794 | Captain T. Judgson. |
| 1801 | Captain G. A. Wood. |
| 1806 | Captain H. D. Ross. |
| 1825 | Captain W. Cator. |
| 1837 | Captain M. Louis. |
| 1837 | Captain W. Dunn. |
| 1841 | Captain W. Bell. |
| 1842 | Captain T. G. Higgins. |
| 1846 | Captain H. G. Teesdale. |
| 1852 | Captain A. J. Taylor. |
| 1854 | Captain A. T. Phillpotts. |
| 1855 | Captain C. S. Henry. |
| 1857 | Captain F. B. Ward. |
| 1858 | Captain G. le M. Tupper. |