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.