The high-road, which runs from Charleroi north through Quatre Bras, Genappe and Waterloo to Brussels, ran between these armies,—that of the Duke of Wellington lying to the westward of the road and that of Marshal Blücher lying to the eastward of it. The Prussians lay considerably closer to the frontier than the English and Dutch. Wellington’s headquarters were at Brussels; Blücher’s at Namur. The turnpike, which runs from Namur through Quatre Bras to Nivelles, was the main avenue of communication between these two armies. The Prussian lines of supply extended by way of Liége and Maestricht to the Rhine; the English by way of Ostend and Antwerp to the sea. The bases of the two armies were thus situated in opposite directions. It was, of course, probable that if either of these armies should be obliged to retreat, it would retreat towards its own base. But to retreat towards its own base would be to march away from its ally. On this peculiarity in the situation Napoleon’s plan of campaign was, to a great degree, founded. The situation was far more favorable for him than if the 220,000 men in Belgium had all belonged to one army, for now, not only were there two armies, under two commanders, in whose operations he might safely count upon the existence of more or less misunderstanding and failure fully to meet each other’s expectations, but the two armies were bound, in case of disaster to either or both, to follow lines of retreat which were wholly divergent. We are now prepared to consider Napoleon’s plan. He proposed to assemble his own forces with all possible secrecy in the neighborhood of Charleroi,—near the point of junction of the two opposing armies. He expected that, on the first news of his approach, the two armies would respectively concentrate, and then endeavor to unite. He expected that the Prussians, being less scattered than the English, and being likely to know of the approach of the French before the English could possibly hear of it, would be the first to concentrate, and he expected therefore to encounter them alone and unsupported by their allies. The statement of Napoleon’s plan of campaign in Gourgaud’s narrative is as follows:—[6] “The Prussian army, having intimation of the enemy’s intentions eight or ten hours before the English, would accordingly be first concentrated. Hopes were even entertained of attacking the Prussians before their four corps were united, or of obliging them to fall back in the direction of Liége and the Rhine, which was their line of operations; and by thus separating them from the English, to create an opportunity for new combinations.