Nevertheless the Imperial army was present, though without Eugene. The whole of the forces were assembled a little to the south of Lille at Orchies; ◆April 20./May 1.◆ and on the 1st of May Marlborough moved forward to a position parallel to that of Villars, who lay in rear of the river Sensée with his left at Oisy and his right at Bouchain. There both armies remained stationary and inactive for six weeks. Eugene came, but presently received orders to return and to bring his troops with him. ◆June 3/14.◆ On the 14th of June Marlborough moved away one march westward to the plain of Lens in order to conceal this enforced diminution of his strength. The position invited a battle, but Villars only moved down within his lines, parallel to the Duke; and once more both armies remained inactive for five weeks. After the departure of Eugene the French commander detached a portion of his troops to the Rhine, but even so he had one hundred and thirty-one battalions against ninety-four, and one hundred and eighty-seven squadrons against one hundred and forty-five of the Allies. We now approach what is perhaps the most remarkable and certainly the most entertaining feat of the Duke during the whole war. Villars, bound by his instructions, would not come out and fight; his lines could not be forced by an army of inferior strength, and they could therefore be passed only by stratagem. The inundation on the Sensée between Arras and Bouchain could be traversed only by two causeways, the larger of which was defended by a strong fort at Arleux, while the other was covered by a redoubt at Aubigny, half a mile below it. Marlborough knew that he could take the fort at Arleux at any time and demolish it, but he knew also that Villars would certainly retake it and rebuild as soon as his back was turned. He therefore set himself to induce Villars to demolish it himself. ◆June 25./July 6.◆ With this view he detached a strong force under General Rantzau to capture the fort, which was done without difficulty. The Duke then gave orders that the captured works should be greatly strengthened, and, for their further protection, posted a large force under the Prussian General Hompesch on the glacis of Douay, some six miles distant from the fort. [Illustration: THE CAMPAIGN OF 1711. _Stanford’s Geogl. Estabt., London._ ]