On the 16th of May, we received intelligence of there being 110,000 French troops in our front. On the 1st of June, it was rumoured that we were to be attacked; Napoleon was to be at Laon on the 6th, and extraordinary preparations were being made for the conveyance of troops in carriages from Paris to the frontiers. Intelligence reached the Duke, on the 10th of the same month, that Napoleon had arrived at Maubeuge, and was passing along the frontier. On the 12th, it was ascertained, for certain, that the French army had assembled and was about to cross the frontiers[7]; but the Duke, for reasons we shall hereafter give, did not think proper to move his troops until quite satisfied as to the point where Napoleon would make his attack; that point proved to be Charleroi, on the high-road to Brussels, on the left of the allied and right of the Prussian armies, said to be the most favourable for defeating the two armies, in detail; which I am inclined to doubt. Situated as the allied and Prussian armies were, Napoleon, by attempting to wedge his army in between the two, was pretty certain of having both upon him: he could not aim a blow at one enemy without being assailed in flank or rear by the other.
Brussels, the capital of Belgium, lies in the very centre of that country, which was declared by general Gneisenau, chief of the Prussian staff, to be a formidable bastion, flanking efficaciously any invasion meditated by France against Germany, and serving at the same time as a tête de pont to England.
Napoleon had numerous partisans and friends in Belgium, who secretly espoused his cause, and who, no doubt, would have seconded him in his attempt to again annex that country to the French Empire. The people also were by no means reconciled to the union forced upon them by the congress of Vienna, a union with a country differing from them in religion and customs; and the dense population and troops of Belgium might probably have made a movement in favour of the French, had Napoleon obtained possession of the capital. From the tenor of Napoleon’s letter to Ney, and his proclamations to his army and to the Belgians[8], it is quite evident that the Emperor expected a manifestation of this kind. This would certainly have added to his cause that moral force of which it stood so much in need, and have induced thousands to rally round the Imperial eagles.
Brussels was our main line of operations and the line of communication with Ostend and Antwerp, the dépôts where our reinforcements and supplies were landed. The Duke, in consequence, saw clearly, it was of the utmost importance, both in a military and political point of view, to preserve an uninterrupted communication with those ports, and that the enemy should not, even for a moment, obtain possession of Brussels[9].
By the Emperor’s masterly arrangements his army was assembled on the frontiers with astonishing secrecy; but his intention of taking the two armies by surprise was defeated, on the night of the 13th, by the Prussian outposts, in advance of Charleroi, having observed the horizon illumined by the reflection of numerous bivac fires in the direction of Beaumont and Maubeuge, which announced that a numerous enemy had assembled in their immediate front; this intelligence was forthwith transmitted to both Wellington and Blücher.
Zieten, the Prussian commander at Charleroi, received intelligence, on the afternoon of the 14th, that the enemy’s columns were assembling in his front, the certain prelude to an attack, probably the next day. Blücher, apprized of this about ten o’clock the same evening, immediately sent off orders for the concentration of the Prussian army at Fleurus, a preconcerted plan between the two commanders. When the order was first sent to Bulow at Liège, to move to Hannut, had the most trifling hint been given him of the French being about to attack, he would probably have been up in time to share in the battle of Ligny, which might have changed the aspect of affairs.
After dispatching orders for the concentration of the Grand army, Napoleon left Paris on the 12th, and, as he himself states, under a great depression of spirits, aware he was leaving a host of enemies behind, more formidable than those he was going to confront. He slept at Laon, and arrived at Avesnes on the 13th, near which place he found his army assembled, amounting, according to his own account, to 122,400 men and three hundred and fifty guns. Their bivacs were behind small hills, about a league from the frontier, situated so as to be concealed, in a great measure, from the view of their opponents.
The Emperor’s arrival amongst his devoted soldiers raised their spirits to the highest degree of enthusiasm, and on the 14th he issued the following order:
“Imperial head-quarters, 14th June, 1815.
“Napoleon, by the grace of God and the constitution of the Empire, Emperor of the French, etc.