Napoleon's intention had been to bring his whole army across the Sambre on the 15th, to occupy Fleurus in force, in anticipation of battle with Blucher, and to send a detachment to Quatre-Bras, where the Charleroi-Brussels road crosses the Namur-Nivelles road, in order to intercept the main line of communication between Wellington and Blucher. This was only approximately carried out: at nightfall, some French divisions were still on the wrong side of the Sambre. Quatre-Bras was found to be occupied, and the French left therefore did not go beyond Frasne, two or three miles to the south; and Ziethen's rear-guard still held Fleurus. The difference was of no serious consequence, the less so as the allied generals played into Napoleon's hands, Blucher by committing himself to battle with only three-fourths of his army and with no assurance of assistance from his colleague, Wellington by his slowness in concentrating his army. The English general, ill served as to intelligence, only heard the news of the French advance in the afternoon: even then, slow to abandon his belief that Napoleon would try to cut him off from the sea, he only warned his troops to be ready. In the evening he ordered concentration on Nivelles, and not till the morning of the 16th did he direct movements on Quatre-Bras.[74] On the morning of June 16 Napoleon was in no hurry to move. He had entrusted Ney with the command of his left wing, and given him orders to attack the English at Quatre-Bras. There was much delay, which seems attributable partly to Ney's doing nothing to hasten the march (he had only joined the army on the 15th and had no staff), and partly to the remissness of the corps commanders, Reille and D'Erlon. About two o'clock however he began, with Reille's corps only, the battle of Quatre-Bras. It was extremely fortunate for Wellington that Ney had not moved earlier, for the position at daybreak was only held by one brigade, and it was but slowly that fresh troops came up. At first the French seemed likely to carry all before them: the Dutch-Belgian troops suffered severely, and some of them fled. No reader of _Vanity Fair_ can have forgotten Thackeray's description of the panic caused in Brussels by the arrival of these fugitives, reporting that the allied army was cut to pieces. The Brunswick division was also broken for the time, and their duke killed.[75] But reinforcements came up in succession, and Wellington, who was on the field in person, grew relatively stronger as evening approached, and foiled every effort Ney made. Why Ney did not make greater efforts, why especially he made so little use of his cavalry, of which arm Wellington had very few on the field, is hard to say. Possibly his Peninsular experiences made him feel convinced that Wellington would not risk a battle without adequate strength. Certainly the woods interfered with his seeing fully the amount of Wellington's force. The absence of D'Erlon's corps