The concentration was in full swing, with the exception of Grouchy’s Reserve Cavalry, when Napoleon left Paris on the night of 11th June. Grouchy had not received his orders for concentration from Soult, the Chief of the Staff, who had neglected to send them until the 12th. Here was an omission at the outset which might well have had serious results. But Grouchy lost no time in setting his Corps on their roads, and by rapid marching he had all his cavalry beyond Avesnes on the night of the 13th. On the evening of the 14th Napoleon moved his headquarters to Beaumont. The First Corps was on the extreme left, between Maubeuge and Solre-sur-Sambre; the Second Corps between Solre-sur-Sambre and Leers; the Third and Sixth Corps between Beaumont and the Sambre; the Fourth Corps between Phillippeville and Florenne; Grouchy’s Reserve Cavalry between Beaumont and Phillippeville; the Imperial Guard at Beaumont. This concentration was brilliantly planned, and skilfully executed: worthy of Napoleon’s best days. The French army crossed the frontier early in the morning of the 15th of June, in three columns. The left column (d’Erlon’s and Reille’s Corps) crossed by Thuin and Marchienne; the centre column (Vandamme’s, Lobau’s Corps, Imperial Guard, and Grouchy’s Reserve Cavalry), at whose head was the Emperor himself, crossed by Ham-sur-Heure, Jamioux, and Marcinelle; the right column, Gérard’s Corps, by Florennes and Gerpinnes. The front was covered by twelve regiments of cavalry. The arrangements for relieving the troops of a fatiguing march by avoiding the crossing of columns in front of each other, and for the communication between each column, were admirable. The baggage and ammunition waggons, except those of the latter which were required for immediate use, were kept 9 miles in rear of the army. The advanced guards of the different columns communicated constantly with each other, so that no column should get ahead of the others. A screen of scouts was sent out in all directions to obtain every scrap of information as to the enemy’s position, and report direct to the Emperor. Everything was to be done to ensure the rapid march of a well-concentrated army on the point where it was expected that the Prussians would be met with. But three of the Corps commanders failed to carry out their instructions. D’Erlon started from his camp at half-past four instead of at three o’clock, as ordered. Vandamme never knew of the march of the army until Lobau’s Corps pushed on his rear: the orders sent to him from headquarters had not reached him, owing to an accident to the officer sent by Soult. And Gérard, who should have marched at three, did not reach Florennes until 7 A.M. All this was carelessness. Soult should have sent such important orders in duplicate. It is interesting to observe how these delays affected the subsequent movements of the columns on the 15th.