The distance over which these notes had to be carried to and fro, from Napoleon to Ney, was not quite five miles. The Emperor might therefore fairly expect after his last message that in the late middle of the afternoon—say half-past five or six—troops would appear upon his north-west horizon and march down to his aid. In good time such troops did appear; how inconclusively it will be my business to record.
Meanwhile, Napoleon had begun the fight at Ligny with his usual signal of three cannonshots, and between three and four o’clock the front of the whole army was engaged. It was for many hours mere hammer-and-tongs fighting, the French making little impression upon their right against Ligny or the villages to the east of it, but fighting desperately for St Amand and for Wagnelée. Such a course was part of Napoleon’s plan, for he had decided, as I have said, only to hold the Prussian left, to strike hardest at their right, and, when his reinforcement should come from Ney, to turn that right, envelop it, and so destroy the whole Prussian army.
These villages upon the Prussian right were taken and retaken in a series of furious attacks and counter-attacks, which it would be as tedious to detail as it must have been intolerable to endure.
All this indecisive but furious struggle for the line of villages (not one of which was as yet carried and held permanently by the French) lasted over two hours. It was well after five o’clock when there appeared, far off, under the westering sun, a new and large body of troops advancing eastward as though to reach that point between Wagnelée and St Amand where the left of the French force was struggling for mastery with the right of the Prussians. For a moment there was no certitude as to what this distant advancing force might be. But soon, and just when fortune appeared for a moment to be favouring Blucher’s superior numbers and the French line was losing ground, the Emperor learned that it was his First Army Corps, under the command of Erlon which was thus approaching.
At that moment—in the neighbourhood of six o’clock in the evening—Napoleon must have believed that his new and rapidly formed plan of that afternoon, with its urgent notes to Quatre Bras and its appeal for reinforcement, had borne fruit; a portion at least of Ney’s command had been detached, as it seemed, to deliver that final and unexpected attack upon the Prussian flank which was the keystone of the whole scheme.
Coincidently with the news that those distant advancing thousands were his own men and would turn this doubtful struggle into a decisive victory for the Emperor came the news—unexplained, inexplicable—that Erlon’s troops would advance no further! That huge distant body of men, isolated in the empty fields to the westward; that reinforcement upon which the fate of Napoleon and of the French army hung, drew no nearer. Watched from such a distance, they might seem for a short time to be only halted. Soon it was apparent that they were actually retiring. They passed back again, retracing their steps beyond the western horizon, and were lost to the great struggle against the Prussians. Why this amazing countermarch, with all its catastrophic consequences was made will be discussed later. It is sufficient to note that it rendered impossible that decisive victory which Napoleon had held for a moment within his grasp. His resource under such a disappointment singularly illustrates the nature of his mind.
Already the Emperor had determined, before any sign of advancing aid had appeared, that if he were left alone to complete the decision, if he was not to be allowed by fate to surround and destroy the Prussian force, he might at least drive it from the field with heavy loss, and, as far as possible, demoralised. In the long struggle of the afternoon he had meant but to press the Prussian line, while awaiting forces that should complete its envelopment; these forces being now denied him, he determined to change his plan, to use his reserves, the Guard, and to drive the best fighting material he had, like a spearhead, at the centre of the Prussian positions. Since he could not capture, he would try and break.
As the hope of aid from Erlon’s First Corps gradually disappeared, he decided upon this course. It was insufficient. He could not hope by it to destroy his enemy wholly. But he could drive him from the field and perhaps demoralise him, or so weaken him with loss as to leave him crippled.
Just at the time when Napoleon had determined thus to strike at the centre of the Prussian fine, Blucher, full of his recent successes upon his right and the partial recapture of the village of St Amand, had withdrawn troops from that centre to pursue his advantage. It was the wrong moment. While Blucher was thus off with the bulk of his men towards St Amand, the Old Guard, with the heavy cavalry of the Guard, and Milhaud’s cavalry as well—all Napoleon’s reserve—drew up opposite Ligny village for a final assault.
Nearly all the guns of the Guard and all those of the Fourth Corps crashed against the village to prepare the assault, and at this crisis of the battle, as though to emphasise its character, a heavy thunderstorm broke over the combatants, and at that late hour (it was near seven) darkened the evening sky.