After much deliberation, and a due consideration of what could be effected by the diminished force now at his disposal, which, by the successive drafts to Eugene's army, was now reduced to one hundred and nineteen battalions, and two hundred and fifty-six squadrons, not mustering above seventy-five thousand combatants, Marlborough determined to break through the enemies' boasted lines; and, after doing so, undertake the siege of Bouchain, the possession of which would give him a solid footing within the French frontier. With this view, he had long and minutely studied the lines of Villars; and he hoped that, even with the force at his disposal, they might be broken through. To accomplish this, however, required an extraordinary combination of stratagem and force; and the manner in which Marlborough contrived to unite them, and bring the ardent mind and lively imagination of his adversary to play into his hands, to the defeat of all the objects he had most at heart, is perhaps the most wonderful part of his whole military achievements.[35]
During his encampment at Lewarde, opposite Villars, the English general had observed that a triangular piece of ground in front of the French position, between Cambray, Aubanchocil-au-bac, and the junction of the Sauzet and Scheldt, offered a position so strong, that a small body of men might defend it against a very considerable force. He resolved to make the occupation of this inconsiderable piece of ground the pivot on which the whole passage of the lines should be effected. A redoubt at Aubigny, which commanded the approach to it, was first carried without difficulty. Arleux, which also was fortified, was next attacked by seven hundred men, who issued from Douay in the night. That post also was taken, with one hundred and twenty prisoners. Marlborough instantly used all imaginable expedition in strengthening it; and Villars, jealous of a fortified post so close to his lines remaining in the hands of the Allies, attacked it in the night of the 9th July; and, though he failed in retaking the work, he surprised the Allies at that point, and made two hundred men and four hundred horses prisoners. Though much chagrined at the success of this nocturnal attack, the English general now saw his designs advancing to maturity. He therefore left Arleux to its own resources, and marched towards Bethune. That fort was immediately attacked by Marshal Montesquieu, and, after a stout resistance, carried by the French, who made the garrison, five hundred strong, prisoners. Villars immediately razed Arleux to the ground, and withdrew his troops; while Marlborough, who was in hopes the lure of these successes would induce Villars to hazard a general engagement, shut himself up in his tent, and appeared to be overwhelmed with mortification at the checks he had received.[36]