The fiercest shock of battle fell upon the corps of Vandamme and Gerard.  Three times were Gerard’s men driven back by the volleys of the Prussians holding Ligny.  But the French cannon open fire with terrific effect.  Roofs crumble away, and buildings burst into flame.  Once more the French rush to the onset, and a furious hand-to-hand scuffle ensues.  Half stifled by heat, smoke, and dust, the rival nations fight on, until the defenders give way and fall back on the further part of the village behind the brook; but, when reinforced, they rally as fiercely as ever, and drive the French over its banks; lane, garden, and attic once more become the scene of struggles where no man thinks of giving or taking quarter.

Higher up the stream, at St. Amand, Vandamme’s troops fared no better; for Bluecher steadily fed that part of his array.  In so doing, however, he weakened his reserves behind Ligny, thereby unwittingly favouring Napoleon’s design of breaking the Prussian centre, and placing its wreckage and the whole of their right wing between two fires.  The Emperor expected that, by 6 o’clock, Ney would have driven back the Anglo-Dutch forces, and would be ready to envelop the Prussian right.  That was the purport of Soult’s despatch of 3.15 p.m. to Ney:  “This army [the Prussian] is lost, if you act with vigour.  The fate of France is in your hands.”

But at 5.30, when part of the Imperial Guard was about to strengthen Gerard for the decisive blow at the Prussian centre, Vandamme sent word that a hostile force of some twenty or thirty thousand men was marching towards Fleurus.  This strange apparition not only unsteadied the French left:  it greatly perplexed the Emperor.  As he had ordered first Ney and then D’Erlon to march, not on Fleurus, but against the rear of the Prussian right wing, he seems to have concluded that this new force must be that of Wellington about to deal the like deadly blow against the French rear.[490] Accordingly he checked the advance of the Guard until the riddle could be solved.  After the loss of nearly two hours it was solved by an aide-de-camp, who found that the force was D’Erlon’s, and that it had retired.

Meanwhile the battle had raged with scarcely a pause, the French guns working frightful havoc among the dense masses on the opposite slope.  And yet, by withdrawing troops to his right, Bluecher had for a time overborne Vandamme’s corps and part of the Young Guard, unconscious that his insistence on this side jeopardized the whole Prussian army.  His great adversary had long marked the immense extension of its concave front, the massing of its troops against St. Amand, and the remoteness of its left wing, which Grouchy’s horsemen still held in check; and he now planned that, while Bluecher assailed St. Amand and its hamlets, the Imperial Guard should crush the Prussian centre at Ligny, thrust its fragments back towards St. Amand, and finally shiver the greater part of the Prussian army on the anvil which D’Erlon’s