Blücher's Prussian army of 116,000 men, with headquarters at Namur, was distributed as follows:—
I. Corps (Zieten), 30,800, cantoned along the Sambre, headquarters Charleroi, and covering the area Fontaine l'Évêque-Fleurus-Moustier.
II. Corps (Pirch I.), 31,000, headquarters at Namur, lay in the area Namur-Hannut-Huy.
III. Corps (Thielemann), 23,900, in the bend of the river Meuse, headquarters Ciney, and disposed in the area Dinant-Huy-Ciney.
IV. Corps (Bülow), 30,300, with headquarters at Liége, around that place.
The frontier in front of Binche, Charleroi and Dinant was watched by the Prussian outposts.
Thus the allied front extended for nearly 90 m. across Belgium, and the mean depth of their cantonments was 30 m. To concentrate the whole army on either flank would take six days, and on the common centre, about Charleroi, three days.
The allies had foreseen the very manœuvre that Napoleon designed to put into execution, and had decided that if an attempt were made to break their centre they would concentrate forwards and on their inner flanks, the Anglo-Dutch army forming up at Gosselies and the Prussians at Fleurus. Here they would be in contact, and ready to act united against Napoleon with a numerical superiority of two to one. The necessary three days' warning of the French concentration they felt certain they would obtain, for Napoleon's troops were at this juncture distributed over an area (Lille-Metz-Paris) of 175 m. by 100 m., and to concentrate the French army unknown to, and unobserved by, the allies, within striking distance and before they had moved a man to meet the onrush of the foe, was unthinkable. But, as in 1800, it was the unthinkable that happened.
It will be seen that Blücher covered Fleurus, his concentration point, by Zieten's corps, in the hope of being able to collect his army round Fleurus in the time that Zieten would secure for him by a yielding fight. Wellington on the other hand was far less satisfactorily placed; for in advance of Gosselies he had placed only a cavalry screen, which would naturally be too weak to gain him the requisite time to mass there. Hence his ability to concentrate hung on the mere good luck of obtaining timely information of Napoleon's plans, which in fact he failed to obtain. But the two tracts of country covered by the allies differed vastly in configuration. Blücher's left was protected by the difficult country of the Ardennes. On the other hand, the duke's whole section lay close to an open frontier across which ran no fewer than four great roads, and the duke considered that his position “required, for its protection, a system of occupation quite different from that adopted by the Prussian army.” He naturally relied on his secret service to warn him in such time as would enable him to mass and meet the foe. His reserve was well placed to move rapidly and promptly in any direction and give support wherever required.
The emperor made his final preparations with the utmost secrecy. The Army of the North was to concentrate In three fractions—around Solre, Beaumont and Philippeville—as close to Charleroi as was practicable, and he arranged to screen the initial movements of the troops as much as possible, so as to prevent the allies from discovering in time that their centre was aimed at. He directed that the movements of the troops when they drew near the allied outposts should be covered as far as possible by accidents of ground, for there was no great natural screen to cover his strategical concentration.
Gérard and the IV. Corps from Metz, having the longest distance to go, started first (on June 6), and soon the whole army was The French Concentration. in motion for the selected points of concentration, every effort being made to hide the movements of the concentration every effort being made to hide the movements of the troops. On June 11 Napoleon himself left Paris for the front, and by June 14 he had achieved almost the impossible itself, for there, at Solre, Beaumont and Philippeville, lay his mass of men, 124,000 strong, concentrated under his hand without rousing the enemy's suspicions, and ready to march across the frontier at dawn. Far different were things on the other side of the Sambre. The allies were still resting in fancied security, dispersed throughout widely distant cantonments; for nothing but vague rumours had reached them, and they had not moved a man to meet the enemy.
The opposing armies were of very different quality. Wellington's was a collection of many nationalities, the kernel being composed of his trusty and tenacious British and King's German Legion troops, numbering only 42,000 men. Of the remainder many were far from enthusiastic in the cause for which they had perforce to take up arms, and might prove a source of weakness should victory incline to the French eagles. Blücher's army was undoubtedly more homogeneous, and though it is doubtful if he possessed any troops of the same quality as Wellington's best, on the other hand he had no specially weak elements.
Napoleon was at the head of a veteran army of Frenchmen, who worshipped their leader and were willing to die for France if necessity demanded. But there were lines of weakness, too, in his army. He had left Marshal Davout behind in Paris, and Murat in disgrace; Suchet was far off on the eastern frontier, and Clausel was in the south of France. The political reasons for these arrangements may have been cogent, but they injured France at the very outset. Marshal Soult was appointed chief of the staff, a post for which he possessed very few qualifications; and, when the campaign began, command of the left and right wings had perforce to be given to the only two marshals available, Ney and Grouchy, who did not possess the ability or strategic skill necessary for such positions. Again, the army was morally weakened by a haunting dread of treason, and some of the chiefs, Ney for example, took the field with disturbing visions of the consequences of their late betrayal of the Bourbon cause, in case of Napoleon's defeat. Finally, the army was too small for its object. Herein Napoleon showed that he was no longer the Napoleon of Austerlitz; for he left locked up in far-distant secondary theatres no less than 56,500 men, of whom he could have collected some 30,000 to 36,000 for the decisive campaign in Belgium. Had he made in 1815 the wise distribution of his soldiers in the theatre of war which he made in his former immortal campaigns he would have concentrated 155,000 to 160,000 of his available force opposite to Charleroi on June 14, and the issue of the campaign would hardly have been in doubt. But he failed to do so, and by taking the field with such inferior numbers he left too much to Fortune.
For his advance into Belgium in 1815 Napoleon divided his army into two wings and a reserve. As the foe would he away to his right and left front after he had passed the Sambre, one wing would be pushed up towards Wellington and another towards Blücher; whilst the mass of the reserve would be centrally placed so as to strike on either side, as soon as a force of the enemy worth destroying was encountered and gripped To this end he had, on the 14th, massed his left wing (Reille and D'Erlon) around Solre, and his right wing (Gérard) at Philippeville, whilst the central mass (Vandamme, Lobau, the Guard and the Cavalry Reserve) lay around Beaumont.
The orders for the French advance next day, among the finest ever issued, directed that the army should march at dawn and move to the Sambre at Marchienne and Charleroi. By evening it was expected that the whole would have crossed the Sambre, and would bivouac between the sundered allies. But at the very outset delays occurred. Owing to an accident that befell the single orderly dispatched with orders for Vandamme, the III. Corps remained without other definite The passage of the Sambre. orders than those issued on June 13, warning them to passage to be ready to move at 3 a.m. The corps therefore stood fast on the morning of June 15, awaiting further instructions. This was the more unfortunate as Vandamme was destined to lead the advance on Charleroi by the centre road. But the emperor regarded it merely as “an unfortunate accident,” nothing more, and the advance in two wings and a reserve continued, undisturbed by such occurrences.
Gérard, too, was late in starting, for his corps had not been fully concentrated over-night. Zieten's outposts on the right bank of the Sambre gained still further time, for they fought stubbornly to retard the French advance on Marchienne and Charleroi. But Zieten declined, and very wisely, to fight on the right bank, and he made the most of the screen afforded by the little river. He had to delay the French advance for 24 hours
