THE WATERLOO CAMPAIGN
�Three memorable days in June 1815�
Captain Cavali� Mercer held the rank of �second captain� in �U� Troop. The Troop was in fact commanded by Sir Alexander Dickson; but as he was temporarily assigned to other duties it was Mercer who was left in command at Waterloo. It was a fine troop, perfect in drill and splendidly horsed, composed of the best elements of 2 Horse Artillery Troops broken up after Napoleon�s exile on Elba.
�G� took the best picked horses of both batteries. �...thus,� says Mercer proudly �making it the finest Troop in the service.� The Troop was made up of 80 gunners and 84 drivers who drove no less than 226 horses.
Indeed, in the Grand Cavalry Review held at Gramont, on the eve of the battle, the Duke of Wellington Brought the Prussian Prince Blucher�s attention to what he called �the beautiful Battery�, whereupon Blucher exclaimed �Mein Gott, dere is not von orse in dies batterie which is not good for Veldt Marshall� (Capt. Mercer�s �Journal of the Waterloo Campaign).
On the 16 June the Battery moved forward to the field of Quatre Eras close to the advancing French Army, traveling 38 miles that day over baggy, congested tracks with their 9 pounders.
The French advanced all day long on the sixteenth and by the 17 June, the British were retreating towards Waterloo. Mercer�s Troop were ordered to cover the retreat as the British Cavalry and Prussian Infantry Began to panic. Mercer�s opened fire on the French Cavalry Squadrons at a range of 1,200 yards and the French called off the chase, allowing the British to escape intact.
Night fall came late on the 17 June and it was a miserable night for Mercer�s men �...seated on a few small twigs, or a little straw, in a newly ploughed field., well soaked with 6 hours heavy rain; their feet 8 inches deep in mud; a thin blanket their only shelter...cold, wet, hungry, without a fire, without meat or drink. And thus they tried to sleep after 48 hours on the march; but few managed it� (Lieutenant Hope -Private Letter).
The Battle of Waterloo began at about 11a.m. on the 18 June. Wellington had lost a quarter of his cavalry killed or injured in the first 90 minutes of fighting and the Allied troops appeared much shaken.
The Battle raged on into the afternoon with Wellington�s position looking more fateful by the minute. Then, at about 3.15 pm, the French launched 3 full divisions of cavalry against the Allied infantry. The situation was desperate. �G� Troop were ordered to abandon their guns when the French Cuirassiers were upon them and then to take shelter in the infantry square.
Mercer did neither! The suspect Brunswick Infantry seemed ready to throw down their arms and flee. Mercer saw this and was convinced that if the Horse Artillery retreated the Brunswickers would run away. His Battery stood firm under their Battery Commander, indeed Mercer�s Troop was the only Battery on The field of battle to drive the French Cavalry off unaided.
A French soldier wrote: �...through the smoke I saw the English gunners abandon their pieces, all but 6 gun (Mercer�s Troop) stationed under the road...now, I thought, those gunners will be cut to pieces, but no, the devils kept firing with grapeshot which mowed us down like grass.�
Captain Mercer disobeyed the orders of the Duke of Wellington, by standing firm; his unrivalled gunners took a terrible toll of the French Cavalry. In all the Troop suffered 14.0 horses dead or injured and it fired a total of 700 rounds; more than any other Horse Artillery Troop in the battle.
The fighting around Mercer�s men had been so intense that one English General said after the battle he �...could plainly distinguish the position of �G� Troop from the other side of the battlefield by the dark mass of dead French Cavalry which, even at that distance, formed a remarkable feature on the battlefield.� (Sir Augustus Frazer).
Had Mercer abandoned the guns the outcome could have been very different indeed. As it was the Battle of Waterloo was won by the evening of the 18 June 1815. Mercer was promoted after the battle and sent to command �D� Troop RHA.