The Prussian Second Corps, under Pirch I., reached Sombreffe by ten o’clock at night; the Third Corps passed the night at Namur; while the Fourth Corps was still near Liège. On Wellington’s side, Van Merlen, commanding the outposts between Mons and Binche, received the report from General Steinmetz at 8 A.M., to the effect that the French had attacked and driven in his outposts, and that he was falling back on Charleroi with his Division. Early in the morning the troops of Perponcher’s Dutch-Belgian Division, which was stationed at Hautain-le-Val, Frasnes, and Villers Perruin, heard firing from the direction of Charleroi. In the afternoon, definite news reached them of the enemy’s attack on Charleroi, and Perponcher at once assembled his First Brigade (Bylandt’s) at Nivelles. A picquet of the Second Nassau battalion was posted in front of Frasnes to give warning of the French advance. In the meantime, Prince Bernard of Saxe Weimar, with his Brigade of Nassau troops, belonging to Perponcher’s Division, on his own initiative moved forward from Genappe to Frasnes, reporting his action to the headquarters of his division at Hautain-le-Val; and Perponcher approved. When Ney advanced on Frasnes in the evening, with Piré’s cavalry and Bachelu’s infantry, Saxe Weimar, after making a determined show of resistance, skilfully withdrew behind Quatre-Bras, and Ney, as before-mentioned, was quite deceived as to his actual strength, and forebore to attack that night. Zieten’s report to Wellington, sent off from Charleroi at 5 A.M., reached the Duke’s headquarters at Brussels at 9 A.M. Wellington did not consider the news sufficiently definite to cause him to make any immediate alteration in his dispositions. But at three o’clock in the afternoon, the Prince of Orange, coming from the outposts near Mons, where he had seen Van Merlen, and obtained information of the attack on the Prussians and of their retreat, reported his intelligence to the Duke. Wellington was now satisfied of the true direction of the French attack, but he sent orders to General Dornberg at Mons to report at once any movement of the French in that direction. He then ordered his troops to concentrate at their respective headquarters. On the left, Perponcher’s and Chassé’s Divisions were to assemble at Nivelles; the Third British Division (Alten’s) was to concentrate at Braine-le-Comte and march on Nivelles in the night; the First British Division (Cooke’s) was to assemble at Enghien. In the centre, Clinton’s Division (the Second British) was to collect at Ath, and Colville’s (the Fourth British) at Grammont. On the right, Steedman’s Division and Anthing’s Brigade of Dutch-Belgians were to march on Sotteghem. Uxbridge’s cavalry was to assemble at Ninove, except Dornberg’s Brigade, which was to march on Vilvorde; (still Wellington had apprehensions for his right). The Reserve was kept in readiness in and around Brussels; with orders to be prepared to march at once.