The Emperor had in the field 72,000 men, all French veterans—each of whom was, as he declared, worth one Englishman and two Prussians, Dutch or Belgians. Napoleon's forces, however, unlike those of Wellington's, had been on the march all through the tempestuous darkness, many of them had not had sufficient food, and the greater part of them did not reach the heights of La Belle Alliance until the morning of the 18th was considerably advanced. The Duke's followers had by that time had refreshment and some hours of repose.
At 1 o'clock in the morning, the Emperor having issued the necessary orders for the battle during the earlier part of the night, went out on foot, accompanied by his grand marshal, and visited the whole line of the main guards. The forest of Soignies, occupied by the British, appeared as one continued blaze, while the horizon between that spot and the farms of La Belle Alliance and La Haye Sainte, was brightened by the fires of numerous bivouacs; the most profound silence reigning. Some time later the rain began to fall in torrents. Napoleon feared more than anything else that Wellington would continue his retreat on Brussels and Antwerp,—thus deferring the great battle until the Russians should approach the valley of the Rhine. The night of June 17-18, often called the "Vigil of Waterloo" was solemn, dark and without unusual incident during the early hours. Several officers sent to reconnoitre, and others who returned to headquarters at half-past three, announced that the British had made no movement. At 4 o'clock the scouts brought in a peasant, who had served as a guide to a brigade of English cavalry which had proceeded to secure a position on the left at the village of Ohain. Two Belgian deserters, who had just quitted their regiments, also reported that their army was preparing for a battle; and that no retrograde movement had taken place; that Belgium prayed for the success of the Emperor, as the English and Prussians were alike unpopular.
The French troops bivouacked amidst deep mud and the officers thought it impossible to give battle on the following day; the ground being so moistened that artillery and cavalry could not possibly manoeuvre, while it would require twelve hours of fine weather to dry the soil. On reaching the eminence of La Belle Alliance at sunrise, and beholding the enemy drawn up on the opposite side and in battle array, the Emperor exclaimed, with evident joy, "At last! at last, then, I have these English in my grasp!" And yet, at this time, his exertions had been most phenomenal, and he was far from being in the physical condition necessary for such a contest as he had every reason to expect. He had been eighteen hours in the saddle on June 15th, and had slept but three hours before the battle of Ligny. On the 16th he was again for eighteen hours on horseback. On the 17th he rose at five in the morning and that night was almost continually astir.
The Emperor's breakfast was served at 8 o'clock and many officers of distinction were present. "The enemy's army" said Napoleon, "is superior to ours by nearly a fourth; there are, nevertheless, ninety chances in our favor, to ten against us." The Emperor now mounted his horse, and rode forward to reconnoitre the English lines; after which he remained thoughtful for a few moments, and then dictated the order of battle. It was written down by two generals seated on the ground, after which two aides-de-camp promptly distributed it among the different corps. The army moved forward in eleven columns, and as they descended from the heights of La Belle Alliance the trumpets played "To the Field!" and the bands alternately struck up airs which recalled the memories of many victories.
The French line of battle was formed in front of Planchenois, having the heights of La Belle Alliance in the rear of its centre. The forces were drawn up in six lines, on each side of the causeway of Charleroi. The first and second lines were of infantry, having the light cavalry at each of its wings, so as to unite them with the six lines of the main force. The artillery was placed in the intervals between the brigades. All the troops were in their stations by about 10:30 o'clock.
Amidst this mass of men there was an almost painful silence until the Emperor rode through the ranks when he was received with the utmost enthusiasm; then, giving his last orders, he galloped to the heights of Rossome, which commanded a complete view of both armies below, with a considerable range on each side beyond.
While Napoleon's design for making his grand attack from the centre, on La Haye Sainte,—which was directly in front of the enemy's centre,—was preparing, he gave orders for the commencement of the battle.
The grand attack on the centre of the Anglo-Belgian army was to be made by Marshal Ney. The marshal had sent word to Napoleon that everything was ready, and he only awaited the order to begin. Before giving it Napoleon looked over the field of battle and the surrounding country,—the last he was ever to contest. He then perceived a dark mass at a distance in the direction of St. Lambert, where he had ordered Grouchy to send a detachment. The glasses of all the officers were instantly turned towards the object. Some thought it only a mass of dark trees. To remove all doubts the Emperor dispatched General Daumont, with a body of three thousand light cavalry, to form a junction with them if they were the troops of Grouchy, or to keep them in check if they were hostile. Through a Prussian hussar, who was brought in a prisoner, it was learned that the dark mass was the advanced guard of Bulow, who was coming up with thirty thousand fresh men; that Blucher was at Wavres with his army, and that Grouchy had not appeared there.
A messenger was immediately dispatched to Marshal Grouchy, to march on St. Lambert, without a moment's delay, and take Bulow's division in the rear. It was believed that Grouchy must be near at hand, whether he had received the various orders sent him or not, as he himself had sent word that he should leave Gembloux in the morning, and from this place to Wavres was only three leagues distance.