It was only on the 20th that two corps of the French 5th Army reached the south bank of the Sambre——one day before Bülow came up on the north, with his VII Corps on his right (west), the X Reserve and X Active Corps as centre, the Guard Active Corps on his left, and the VII Reserve (before Namur) and Guard Reserve Corps in support. In this posture, on the evening of August 20, Lanrezac received General Joffre’s order to strike across the Sambre. Namur was then garrisoned by the Belgian 4th Division, to which was added, on the 22nd, part of the French 8th Brigade under General Mangin. Lanrezac had not even been able to get all his strength aligned on the Sambre when the shock came.[23] On the 21st, his five corps were grouped as follows: The 1st Corps (Franchet d’Espérey) was facing east toward the Meuse north of Dinant, pending the arrival, on the evening of the 22nd, of the Bouttegourd Reserve Division; the 10th Corps (Defforges), with the 37th (African) Division, on the heights of Fosse and Arsimont, faced the Sambre crossings at Tamines and Auvelais; the 3rd Corps (Sauret) stood before Charleroi, with the 38th (African) Division in reserve; the 18th Corps (de Mas-Latrie) was behind the left, south of Thuin. Of General Valabrègue’s group of reserve divisions, one was yet to come into line on the right and one on the left. Could Lanrezac have accomplished anything by pressing forward into the unknown with tired troops? The question might be debatable had the Allies had only Bülow to deal with; but, as we shall see, this was by no means the case. Meanwhile, the British made a day’s march beyond the Sambre. On the 22nd they continued the French line west-north-westward, still without an enemy before them, and entrenched themselves, the 5th Cavalry Brigade occupying the right, the 1st Corps (Haig) from Binche to Mons, and the 2nd Corps (Smith-Dorrien) along the canal to Condé-on-Scheldt. West and south-west of this point, there was nothing but the aforesaid groups of French Territorials. The I German Army not yet having revealed itself, the general idea of the French command, to attack across the Sambre with its centre, and then, if successful, to swing round the Allied left in a north-easterly direction against what was supposed to be the German right flank, still seemed feasible. But, in fact, Kluck’s Army lay beyond Bülow’s to the north-west, on the line Brussels–Valenciennes; it is quite possible, therefore, that a preliminary success by Lanrezac would have aggravated the later defeat. [Illustration: Battle of Charleroi–Mons]