Douay, which was immediately invested after this success, is a fortress of considerable strength, in the second line which covers the French province of Artois. Less populous than Lille, it embraces a wider circuit within its ample walls. Its principal defence consists in the marshes, which, on the side of Tournay, where attack might be expected, render it extremely difficult of access, especially in the rainy season. Access to it is defended by Fort Scarpe, a powerful outwork, capable of standing a separate siege. The garrison consisted of eight thousand men, under the command of the Marquis Albergotti, an officer of the highest talent and bravery; and under him were the renowned Valory, to direct the engineers, and the not less celebrated Chevalier de Jaucourt, to command the artillery. From a fortress of such strength so defended, the most resolute resistance might be expected, and no efforts were spared on the part of the Allied generals to overcome it.
The investment was completed on the 24th, and the trenches opened on the 5th May. On the 7th, the head of the sap was advanced to within two hundred and fifty yards of the exterior palisades; but the besiegers that night experienced a severe check from a vigorous sally of the besieged with twelve hundred men, by which two English regiments were nearly cut to pieces. But, on the 9th, a great train of artillery, consisting of two hundred pieces, with a large supply of artillery, arrived from Tournay; on the 11th, the advanced works were strongly armed, and the batteries were pushed up to the covered way, and thundered across the ditch against the rampart. The imminent danger of this important stronghold now seriously alarmed the French court; and Marshal Villars, who commanded their great army on the Flemish frontier, received the most positive orders to advance to its relief. By great exertions, he had now collected one hundred and fifty-three battalions and two hundred and sixty-two squadrons, which were pompously announced as mustering one hundred and fifty thousand combatants, and certainly amounted to more than eighty thousand. The Allied force was almost exactly equal; it consisted of one hundred and fifty-five battalions and two hundred and sixty-one squadrons. Villars broke up from the vicinity of Cambray on the 21st May, and advanced in great strength towards Douay. Marlborough and Eugene immediately made the most vigorous preparations to receive him. Thirty battalions only were left to prosecute the siege; twelve squadrons were placed in observation at Pont-a-Rache; and the whole remainder of the army, about seventy thousand strong, concentrated in a strong position, covering the siege, on which all the resources of art, so far as the short time would admit, had been lavished. Every thing was prepared for a mighty struggle. The whole guns were mounted on batteries four hundred paces from each other; the infantry was drawn up in a single line along the intrenchment, and filled up the whole interval between the artillery; the cavalry were arranged in two lines, seven hundred paces in rear of the foot-soldiers. It seemed another Malplaquet, in which the relative position of the two armies was reversed, and the French were to storm the intrenched position of the Allies. Every man in both armies fully expected a decisive battle; and Marlborough, who was heartily tired of the war, wrote to the Duchess, that he hoped for a victory, which should at once end the war, and restore him to private life.[8]