Notwithstanding all the diligence with which Villars laboured to strengthen his men on this important position, he could not equal the activity with which the English general strove to supplant them. During the night of the 13th, three redoubts were marked out, which would have completed the French marshal's communication with the town. But on the morning of the 14th they were all stormed by a large body of the Allied troops before the works could be armed. That very day the Allies carried their zig-zag down to the very edge of a morass which adjoined Bouchain on the south, so as to command a causeway from that town to Cambray, which the French still held, communicating with the besieged town. But, to complete the investment, it was necessary to win this causeway; and this last object was gained by Marlborough with equal daring and success. A battery, commanding the road, had been placed by Villars in a redoubt garrisoned by six hundred men, supported by three thousand more close in their rear. Marlborough, with incredible labour and diligence, constructed two roads, made of fascines, through part of the marsh, so as to render it passable to foot-soldiers; and, on the night of the 16th, six hundred chosen grenadiers were sent across them to attack the intrenched battery. They rapidly advanced in the dark till the fascine path ended, and then boldly plunging into the marsh, struggled on, with the water often up to their arm-pits, till they reached the foot of the intrenchment, into which they rushed, without firing a shot, with fixed bayonets. So complete was the surprise, that the enemy were driven from their guns with the loss only of six men; the work carried; and with such diligence were its defences strengthened, that before morning it was in a condition to bid defiance to any attack.[42]