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.