There were, to be sure, other courses open to him. He might direct his army upon the communications of the Prussians by passing to the eastward of them and turning their left flank. But this operation involved a wide _détour_ over a difficult country, and in the battle which was certain to result, the Prussian and the English armies would, beyond a doubt, both be united against him. On the other hand he could turn Wellington’s right by moving _viâ_ Lille, Valenciennes or Mons upon Ghent or Brussels. An advance in this direction presented, to be sure, fewer difficulties than the one just spoken of, and promised greater advantages. The Duke himself always maintained that this would have been Napoleon’s best move. It probably would have cut the English communications with Ostend, and would very likely have forced Wellington to evacuate Brussels without a battle, that is, unless he cared to risk an engagement without the aid of his ally. But the Prussians in the meantime would have concentrated without molestation their whole army of 120,000 men, and if Wellington had been successful in avoiding a battle with the French superior force, the two allied generals ought to have been able either to manœuvre Napoleon out of Belgium or to force him to battle on disadvantageous terms. It is probable that in neither of these flanking movements would there be an opportunity afforded for a direct, immediate, crushing blow upon one of the allied armies, such as that which Napoleon thought it very possible that the temerity of Marshal Blücher was going to present to him, if he advanced by way of Charleroi.