Had it not been for Vandamme’s delay, and had Grouchy attacked the Prussians at once at Gilly, the latter could have pushed his enemy as far as Sombreffe that night, which it was Napoleon’s intention that he should have done. But Vandamme’s slowness prevented Grouchy from advancing further than Fleurus that evening.
On the Left, matters had not, by nightfall, progressed as far as Napoleon wished. Reille, in accordance with his instructions, had marched with his Corps, the Second, from Leers at 3 A.M., and pushed on to Marchienne, everywhere driving back the enemy’s outposts. He was then ordered to march on Gosselies, where it was reported that a body of Prussians were in position. He therefore pushed on his troops along the Charleroi-Brussels road; and finding Jumet occupied by a Prussian rearguard, he drove out the enemy, and reached Gosselies at about 5 P.M. Marshal Ney now arrived on the scene, and, having just come from the Emperor, from whom he received his orders, took over the command of the Left Wing. Ney pushed on to Frasnes with Piré’s Cavalry and Bachelu’s Infantry Division: Girard’s Division was sent to pursue the Prussians, who had retreated from Gosselies towards Fleurus: the remaining divisions of Reille’s Corps--Jerome’s and Foy’s--stayed at Gosselies. Ney drove back Saxe-Weimar’s Brigade from Frasnes at 6.30 P.M.; the brigade retiring on Quatre-Bras. Lefebvre-Desnouette’s Division of Light Cavalry of the Guard had arrived with Ney, and was now moved in support of his infantry at Frasnes.
Thus Ney, at 6.30 P.M., while there were still nearly three hours of daylight left, had with him two light cavalry divisions, and one infantry division, at Frasnes. The distance to Quatre-Bras was 2½ miles. In less than an hour he could have reached the cross-roads and attacked Saxe-Weimar’s Brigade. But he merely pushed his cavalry forward, reconnoitred the position, and then withdrew his men to Frasnes, himself returning to Gosselies at about 8.30 P.M.
Now it has been fiercely contested that Ney received verbal orders from Napoleon to occupy Quatre-Bras on the night of the 15th. Whether he did or did not is a point still undecided by the authorities on the campaign, but it matters little, for Napoleon, in his written orders to Ney on the 16th, expressed his satisfaction with the progress of the night before, and did not blame Ney for his failure to occupy the cross-roads. As a matter of fact, Saxe-Weimar made such a bold show of resistance to the reconnaissance sent by Ney, that the latter was entirely deceived as to his enemy’s numbers: he believed that the English were in great force there. Had Ney attacked Quatre-Bras that night, he would have driven back Saxe-Weimar’s Brigade of Nassauers, the only troops in occupation, and seized the most important point in the theatre of war. But, viewing the question from what must have been Ney’s own point of view, he was acting on sound strategical principles by not pushing ahead too far. He had only just arrived on the ground, and was not acquainted with any of his Staff, or his divisional generals, or even with the strength of his troops. He believed that a strong English force held Quatre-Bras, and that, by attacking, he would be overwhelmed by the whole of Wellington’s army; that Napoleon’s Left Wing would be crushed. He therefore adopted more cautious methods, and awaited the arrival of d’Erlon’s Corps, and news of the progress of the Centre and Right Wing.