|Map of the action area for the 100 days Campaign by Columbia Games|
At half past two on the morning of June 15, the first French troops were roused from their bivouacs. Headed by the twelve regiments of cavalry screen, three great columns began to converge systematically on the River Sambre: Reille and d'Erlon toward Marchienne and Thuin respectively; Vandamme, Gerard, Lobau and the Guard on Charleroi. The timetable was carefully regulated in an attempt to avoid congestion and confusion on the crowded roads. Every thirty minutes a new formation was set in motion towards the front; the last units were to be on their way by eight o'clock. All surplus transport -- including the coaches of senior officers -- was ordered to be left behind, the sappers were stationed behind the leading regiment of each column to ensure that the road surfaces and bridges could take the heavy traffic. The marching plans of the various corps were timed to ensure that the heads of the columns reached the Sambre simultaneously on a narrow front of barely five kilometers. Once the crossing had been safely accomplished, the two wings were under orders to push ahead for Fleurus and Frasnes respectively, while the reserve concentrated in and around Charleroi itself. It is important to note that no specific mention was made in the Movement Order (June 14) of the need to physically occupy either Quatre Bras or Sombreffe on the vital lateral road. Doubtless the Emperor would have been quite happy to see his adversaries concentrate still further forward, should they be so foolhardy.
~ D. Chandler, The Campaigns of Napoleon, p. 1026