Waterloo, 18 June 1815: The Royal Horse Artillery Repulse Enemy Cavalry, late afternoon.

Field Captain A.C.Mercer, Royal Horse Artillery.

A heavy Column of Cavalry, composed of Grenadiers à Chevel and Cuirassiers, had just ascended the plateau and was advancing upon us at a rapid pace, so that there was scarcely time even to get into action, and, if caught in column, of course we were lost.

   However, the order was given to deploy, and each gun as it came up immediately opened its fire; the two Infantry squares at the same time commencing a feeble and desultory fire; for they were in such a state that I momentarily expected to see them disband.

   Their ranks, loose and disjointed, presented gaps of several file in breadth, which the Officers and Sergeants were busily employed filling up by pushing or even thumping their men together; whilst these, standing like so many logs, with their arms at the recover, were apparently completely stupefied and bewildered. I should add that they were all perfect children. None of the privates, perhaps were above 18 years of age. In spite of our fire the Column of Cavalry continued advancing at the trot until separated from us by scarcely more than the breadth of the little road, but at the very moment we expected to be overwhelmed, those of the leading Squadrons suddenly turning, and endeavouring to make way to the rear, confusion took place, and the whole broke into a disorderly crowd. The scene that ensued is scarcely to be described. Several minutes elapsed ere they succeeded in quitting the plateau, during which our fire was incessant, and the consequent carnage was frightful, for each Gun (9 Pdrs) was loaded with a round and case shot; all of which, from the shortness of the distance, size of the object, and elevation of the ground on which they stood, must have taken effect.

   Many, instead of seeking safety in retreat, wisely dashed through the intervals between our Guns, and made their way as we had seen others do; but the greater part, rendered desperate at finding themselves held, as it were, in front of our Battery, actually fought their way through their own ranks, and in the struggle we saw blows exchanged on all sides. At last the wreck of this formidable Column gained protection under the slope of the hill, leaving the Plateau encumbered with their killed and wounded, and we then ceased firing, that our men, who were much fatigued with their exertions, might rest themselves and be fresh against the next attack, which we saw preparing; for they had not retired so far down the hill but that the tall caps of the Grenadiers of the leading Squadrons were visible above the brow.

   The second attempt was preluded by a cloud of skirmishers, who, advancing to within a very short distance of our front, did us considerable mischief with their carbines and pistols, but their intention being evidently to draw out our fire, no notice was taken of them.

   At length the Column, being re-formed, again ascended the Plateau, and advanced to attack us, but this time their pace scarcely exceeded a walk, or at most a gentle trot, too many obstacles lying in their way to admit of more rapid movement without confusion. This was in our favour. Experience having shown us the unerring and destructive effects of a close fire, we allowed the leading Squadrons to attain about half the distance between the brow of the slope and the road in our front before we commenced. It is scarcely necessary to say that the result was precisely similar to what has already been detailed. Again they fell into confusion, and again for several minutes were exposed to a deliberate fire of case shot within 20 yards, so that the heap of killed and wounded left on the ground, was now enormous...

   With respect to the appearance of the Field after the Action, not much can be said, for night closed upon us very shortly, and we were too glad to lie down to think of looking about. That the ground was everywhere thickly strewed with the dead and dying (Men and Horses), wrecks of Gun and Ammunition Carriages, Arms, Caps, etc., will occur as a matter of course. I should, however, add that the heap of slaughter was far greater in front of our Battery than on any other part of the Field, so much so that Colonel Sir Augustus Fraser told me two days afterwards at Nivelles that in riding over the French position he could distinctly see where G (our Letter) Troop had stood from the dark pile of bodies in front of it, which was such as even to form a remarkable feature in the field.