On the surrender of Douay, the Allied generals intended to besiege Arras, the _last_ of the triple line of fortresses which on that side covered France, and between which and Paris no fortified place remained to arrest the march of an invader. On the 10th July, Marlborough crossed the Scarpe at Vitry, and, joining Eugene, their united forces, nearly ninety thousand strong, advanced towards Arras. But Villars, who felt the extreme importance of this last stronghold, had exerted himself to the utmost for its defence. He had long employed his troops on the construction of new lines of great strength on the Crinchon, stretching from Arras and the Somme, and he had here collected nearly a hundred thousand men, and a hundred and thirty pieces of cannon. After reconnoitring this position, the Allied generals concurred in thinking that it was equally impossible to force them, and undertake the siege of Arras, while the enemy, in such strength, and so strongly posted, lay on its flank. Their first intention, on finding themselves baffled in this project, was to seize Hesdin on the Cancher, which would have left the enemy no strong place between them and the coast. But the skilful dispositions of Villars, who on this occasion displayed uncommon abilities and foresight, rendered this design abortive, and it was therefore determined to attack Bethune. This place, which was surrounded with very strong works, was garrisoned by nine thousand men, under the command of M. Puy Vauban, nephew, of the celebrated marshal of the same name. But as an attack on it had not been expected, the necessary supplies for a protracted resistance had not been fully introduced when the investment was completed on the 15th July.[12]
Villars, upon seeing the point of attack now fully declared, moved in right columns upon Hobarques, near Montenencourt. Eugene and Marlborough upon this assembled their covering army, and changed their front, taking up a new line stretching from Mont St Eloi to Le Comte. Upon advancing to reconnoitre the enemy, Marlborough discovered that the French, advancing to raise the siege, were busy strengthening a new set of lines, which stretched across the plain from the rivulet Ugie to the Lorraine, and the centre of which at Avesnes Le Comte was already strongly fortified. It now appeared how much Villars had gained by the skilful measures which had diverted the Allies from their projected attack upon Arras. It lay upon the direct road to Paris. Bethune, though of importance to the ultimate issue of the war, was not of the same present moment. It lay on the flank on the second line, Arras in front, and was the only remaining fortress in the last. By means of the new lines which he had constructed, the able French marshal had erected a fresh protection for his country, when its last defences were wellnigh broken through. By simply holding them, the interior of France was covered from incursion, and time gained for raising fresh armaments in the interior for its defence, and, what was of more importance to Louis, awaiting the issue of the intrigues in England, which were expected soon to overthrow the Whig cabinet. Villars, on this occasion, proved the salvation of his country, and justly raised himself to the very highest rank among its military commanders. His measures were the more to be commended that they exposed him to the obloquy of leaving Bethune to its fate, which surrendered by capitulation, with its numerous garrison and accomplished commander, on the 28th August.[13]