The Marshal calculated that if Napoleon had gained a victory, and crossed the Namur road, the longer Wellington remained in the position of Quatre Bras, the greater the danger he incurred of having not only his communication with Blücher effectually cut off, but also his main line of retreat upon Brussels intercepted; and that in such a case it was wiser not to advance against the British General, as the latter might then retire, and thus elude the effect of a combined operation between Napoleon's and his own forces. He also judged that if, on the other hand, the French Emperor had been defeated, an attack made on his own part, upon the Anglo-Allied Army, might subject himself to the risk of having to contend against a combined operation between Wellington and Blücher; and thus expose both his own and Napoleon's forces to the probability of being defeated in detail.
In this uncertainty, Ney sent a message by General Count Flahaut, who happened to be still with him, and who was returning to rejoin the Emperor wherever he might be found, expressive of his anxiety to learn the result of the action of the preceding day. In the mean time, he kept his troops in a state of perfect quietude; his main body was posted in reserve on the Heights of Frasne, between which and the Outposts there were intermediate Columns of Support; but no movement whatever was attempted.
Ney at length received the information he had solicited, in a despatch from Soult, wherein the result of the Battle of Ligny was briefly described. It also stated that Napoleon was proceeding, with the principal portion of his forces, to the Mill of Bry, close to which the high road leads from Namur to Quatre Bras, and that therefore it would not be practicable for the Anglo-Allied Army to act against him (Ney); but that, should such a case happen, the Emperor would march directly upon it by that road, while Ney should attack it in front, and in this manner that Army would at once be destroyed. The despatch required from Ney a report of the exact position of his forces, and an account of all that was going on in his front.
Hence it is evident that Ney's opinion, that a victory at Ligny ought to be followed up by a combined attack upon Wellington, perfectly coincided with Napoleon's views; but while Ney was thus justified in remaining inactive during the early part of the day, the fact of the Emperor's not moving directly upon Genappe with the morning's dawn, and his excessive delay in breaking up his bivouac at Ligny, are inexplicable. A glorious opportunity had presented itself for the attainment of his original design of defeating both Armies in detail, but which was completely lost by a most extraordinary and fatal want of energy and vigour in seizing upon the advantages which the victory of Ligny had placed within his reach.
Ney, having ascertained that Napoleon's forces were in motion, had commenced the advance of his own troops, when a second despatch reached him, dated, "in front of Ligny, at noon," intimating that the Emperor had just posted a Corps of Infantry and the Imperial Guard in advance of Marbais, that he wished him to attack the Enemy at Quatre Bras, and force him from his position; and that his operations would be seconded by the Corps at Marbais, to which point his Majesty was proceeding in person.
Upon discovering that the Anglo-Allied Infantry had retired, and that the troops around, and in rear of, Quatre Bras, consisted of Cavalry covering the retreat, Ney brought forward his own Cavalry in advance, and appeared to regulate its movements so that its attack might be directed against the Front of the British simultaneously with that of the Cavalry which he now perceived advancing along the Namur road against its Flank.
About this time, the 10th Hussars were moved across the Namur road, and down the slope in front where they were halted, in echelon of Squadrons; and while they were thus posted, Wellington and his Staff came to the front of the Regiment. From this spot the Duke was attentively watching, through his telescope, the dispositions and movements of the French, whom he could discover as soon as they reached the Quatre Bras side of Little Marbais; when all at once at a distance of about two miles, masses were seen forming on the side of the Namur road, conspicuously glittering in the sun's rays; by which the Duke was at first induced to believe that they were Infantry, whose bayonets were so brilliantly reflected; but it was soon discovered that they were Cuirassiers.
After a short time, these were observed to advance, preceded by Lancers, and it was not long before the Picquet of the 18th British Hussars, posted on that road, began skirmishing, as did also the Picquet of the 10th British Hussars, more in the front of the position, and likewise, still further to the right, in front of Quatre Bras, a Picquet consisting of a Squadron of the 11th British Light Dragoons, detached from Major General Vandeleur's Brigade, which comprised the 11th Light Dragoons (under Lieutenant Colonel Sleigh), the 12th Light Dragoons (under Colonel the Hon. Frederick Ponsonby), and the 16th Light Dragoons (under Lieutenant Colonel Hay). The 10th Hussars then fell back again into their proper place in the line. Vivian now took up a new alignment, throwing back his Left so as to present a front to the Enemy's advance, and to protect the left of the position. Vandeleur's Brigade was then in Right Rear of Vivian's and close to Quatre Bras.
The Anglo-Allied Infantry having, some time previously, entirely crossed the Genappe, with the exception of the Light Companies of the Second Brigade of Guards on the right, and of the 1st Battalion 95th British Regiment (Rifles), on the left, which troops had been directed to remain until the last moment, and were now retiring to Genappe (where they were subsequently drawn up at the entrance of the town), and the Duke having satisfied himself that a formidable body of the French Cavalry was endeavouring to fall upon him and to molest his retreat, it became a question with his Grace, at that moment, how far it might be advisable to offer any serious resistance to the advance of the Enemy; but Lieutenant General the Earl of Uxbridge, the Commander of the Anglo-Allied Cavalry, having remarked that, considering the defiles in the rear, and the distance to which the great mass of the Infantry had already retired and from which it could offer no immediate support, he did not think the Cavalry was favourably situated for making such an attempt, the Duke assented to the correctness of this view, and requested his Lordship at once to carry into effect the retreat of the Cavalry.
Uxbridge immediately made the following dispositions for this purpose. The First or Household Brigade of Heavy Cavalry commanded by Major General Lord Edward Somerset, and consisting of the 1st Life Guards (under Lieutenant Colonel Ferrior), of the 2nd Life Guards (under Lieutenant Colonel the Hon. Edward P. Lygon), of the Royal Horse Guards, or Blues (under Lieutenant Colonel Sir Robert Chambre Hill), and of the 1st (or King's) Dragoon Guards (under Colonel Fuller), together with the Second Brigade of Heavy Cavalry, commanded by Major General the Honourable Sir William Ponsonby, consisting of the 1st, or Royal Dragoons (under Lieutenant Colonel Clifton), of the 2nd Royal North British Dragoons, or Scots Greys (under Colonel Hamilton), and of the 6th, or Inniskilling Dragoons (under Colonel Muter), formed the Centre Column, which was to retire by the Brussels high road.