Both the British Heavy Cavalry Brigades were now in full retreat. Somerset's regained the position without any serious molestation: but Ponsonby's Dragoons, particularly the Greys, who were upon the extreme Left, suffered severely from Jaquinot's Lancers and Chasseurs, the greater part of them being in a state of the utmost confusion and exhaustion; whilst the latter were infinitely superior in numerical force, were in good order, and mounted on horses perfectly fresh. On their right the Lancers charged in Open Column; the remainder, extending in open Lancer order towards their left, rapidly spread over the plain, darting upon the stragglers and wounded of the British Cavalry who came within their reach; and, at the same time, giving confidence to such of their own scattered Infantry as were still retreating in disorder and confusion.
At length, the Support so greatly needed by Ponsonby's Brigade arrived upon its Left Flank. Vandeleur, having passed the hollow way and ravine which intercepted his progress towards the scene of action, had reached that part of the crest of the position occupied by Best's Hanoverian Brigade, through which it now advanced to the front in Open Column of divisions. The 12th Light Dragoons, being the leading Regiment, moved quickly down the slope: the 16th Regiment remained higher up the acclivity; while the 11th were drawn up in reserve upon the brow of the hill. The 12th and 16th wheeled into Line to their right. Lieutenant Colonel the Hon. Frederick Ponsonby, who commanded the 12th, perceiving the confusion that prevailed amidst the French Infantry in the valley, as also the extremely critical situation of a great number of scattered red coated Dragoons nearly on the crest of the French position, instantly charged a mass of unsteady Infantry which intervened between him and these Dragoons. This Infantry comprised the rearmost supporting Column of Marcognet's Division, and was the only one of the attacking Columns yet intact. It was now destined to share their fate. Already alarmed by the disorder into which the entire of the Infantry on its left had been thrown, and now attacked so suddenly and unexpectedly on its right, it was penetrated by the charge of the 12th.
These Dragoons having forced their way through the Column, whereby their order was naturally much broken, came upon the Right Flank of the Lancers who were in pursuit of Ponsonby's Brigade. Quickening their speed, they dashed in amongst the French Cavalry, and acting almost perpendicularly upon their Flank, they "rolled up" such as were immediately in their front. The 16th Light Dragoons, with Vandeleur at their head, very gallantly charged obliquely upon the front of the Lancers, whose further advance was completely checked by this double attack. On their extreme Right, the 16th rather clashed with some of the retiring Dragoons: but the two Regiments, carrying every thing before them, succeeded in driving the French Light Cavalry down again to the foot of the valley; which they had been ordered, previously to their charge, not to pass.
Some few of both the 12th and 16th did, nevertheless, madly rush up the opposite Height; where, by this time, fresh troops had arrived, who made them suffer for their temerity.
Ghigny's Dutch-Belgian Light Cavalry Brigade, which had, at the commencement of this Cavalry attack, crossed the Charleroi road, came up, in the mean time, to the brow of the main position, on the left of Vandeleur's Brigade. One of its Regiments, the 4th Light Dragoons, went down the slope, following the 12th Light Dragoons; and after experiencing the effects of a brisk fire which was kept up by Durutte's Skirmishers from behind a bank and hedge, low down the slope, and from which the 12th Light Dragoons had previously suffered, it assisted in completing the dispersion of the French Infantry. The other Regiment (the 8th Hussars) remained a few minutes upon the Height, and then advanced to draw off the retiring Cavalry.
Vivian, who had come forward in person from the extreme Left, and proceeded some way down the slope for the purpose of making his observations, upon perceiving Ponsonby's Brigade charging in disorder up the French Heights, immediately sent back word for the 10th and 18th British Hussars to move through the hollow way to their right, leaving the remaining Regiment of his Brigade, the 1st Hussars of the King's German Legion, to keep a look out to the left. Very shortly afterwards, two guns detached in advance from his Horse Battery, drew up on the brow of the main ridge; but had scarcely opened a fire when a well directed shot from one of the French Batteries passed through the ammunition boxes of one of the limbers, causing an explosion, which drew forth a shout of triumph on the part of the French Artillerymen.
The charge of Vandeleur's Brigade having succeeded, without the active aid of even its own immediate Support, the 11th Light Dragoons; the further advance of the 10th and 18th Hussars was not required, but they continued in their new position, on the right of the lane leading to Verd Cocou, and the two guns rejoined their Battery.
Major Whinyates's Rocket Troop, having been brought up to the crest of the main ridge, from its previous position in reserve near Mont St Jean, its Rocket Sections were moved down to the foot of the exterior slope, whence they discharged several rockets at the French troops then formed, or in the act of reforming, upon the opposite heights. Immediately after the execution of this service, which was gallantly and skilfully conducted, the Troop rejoined its guns on the crest of the position.
In the general mêlée which resulted from the charge of the British Heavy Dragoons, and the overthrow of such masses of Infantry, augmented as it was by the subsequent charges of, firstly, the French Lancers, and, then, the two Regiments of British Light Cavalry, severe losses were sustained on both sides; and the British Army was deprived of some of its brightest ornaments.