By thus holding the Prussians at H and pushing them in at D, he would here begin to pen them back, and it needed but the arrival on the field of a fresh French force attacking the Prussians along A B to destroy the force so contained and hemmed in. For that fresh force Napoleon depended upon new and changed instructions which he despatched to Ney when he saw the size of the Prussian force before him. During Napoleon’s main attack, some portion of Ney’s force, and if possible the whole of it, should appear unexpectedly from the north and west, marching down across the fields between Wagnelée and the Nivelles-Namur road, and coming on the north of the enemy at A B, so as to attack him not only in the flank but in the rear. He would then be unable to retreat in the direction of Wavre (W)—a broken remnant might escape towards Namur (N). But it was more likely that the whole force would be held and destroyed.
Elements of Ligny.
Supposing that Napoleon’s 63,000 showed themselves capable of holding, let alone partially driving in, the 80,000 in front of them, the sudden and unexpected appearance of a new force in the height of the action, adding another twenty or thirty thousand to the French troops already engaged, coming upon the flank and spreading to the rear of the Prussian host, would inevitably have destroyed that host, and, to repeat Napoleon’s famous exclamation, “not a gun would have escaped.”
The reader may ask: “If this plan of victory be so obvious, why did Napoleon send Ney off with a separate left wing of forty to fifty thousand men towards Quatre Bras?”
The answer is: that when, upon the day before, the Thursday, Napoleon had made this disposition, and given it as the general orders for that Friday, he had imagined only one corps of Prussians to be before him.
The right wing, with which the Emperor himself stayed, numbering, as we have seen, about 63,000 men, would have been quite enough to deal with that one Prussian corps; and he had sent so large a force, under Ney, up the Brussels road, not because he believed it would meet with serious opposition, but because this was to be the line of his principal advance, and it was his intention to occupy the town of Brussels at the very first opportunity. Having dealt with the single Prussian corps, as he had first believed it would be, in front of Fleurus, he meant that same evening to come back in person to the Brussels road and, in company with Ney, to conduct decisive operations against Wellington’s half of the Allies, which would then, of course, be hopelessly outnumbered.
But when Napoleon saw, a little after midday of the Friday, that he had to deal with nearly the whole of the Prussian army, he perceived that the great force under Ney would be wasted out there on the west—supposing it to be meeting with little opposition—and had far better be used in deciding a crushing victory over the Prussians. To secure such a victory would, without bothering about the Duke of Wellington’s forces to the westward, be quite enough to determine the campaign in favour of the French.
As early as two o’clock a note was sent to Ney urging him, when he had brushed aside such slight resistance as the Emperor expected him to find upon the Brussels road, to return and help to envelop the Prussian forces, which the Emperor was about to attack. At that hour it was not yet quite clear to Napoleon how large the Prussian force really was. This first note to Ney, therefore, was unfortunately not as vigorous as it might have been; though, even if it had been as vigorous as possible, Ney, who had found unexpected resistance upon the Brussels road, could certainly not have come up to help Napoleon with his whole force. He might, however, have spared a portion of it, and that portion, as we shall see later, would have been most obviously Erlon’s corps—the First. Rather more than an hour later, at about a quarter-past three, when Napoleon had just joined battle with the Prussians, he got a note from Ney informing him that the left wing was meeting with considerable resistance, and could hardly abandon the place where it was engaged before Quatre Bras to come up against the Prussian flank at Ligny. Napoleon sent a note back to say that, none the less, an effort must be made at all costs to send Ney’s forces to come over to him to attack the Prussian flank, for such an attack would mean the winning of a great decisive battle.