Only one Allied fortress remained: the city of Oudenaarde. If the French managed to capture that city, Marlborough's army would be cut off from the coast, causing them to lose communication with England. Marlborough managed to guess the French battle plan, and also correctly guessed the method by which the French army would attempt to take Oudenarde- they would march down the east bank of the Scheldt (closer to Marlborough's troops), while leaving a large covering force between the two opposing armies. The French army set out on 8 July, marching toward the city of Lessines. However, Marlborough made one of the most impressive forced marches in history, capturing the city on 10 July. This forced the French commanders to attempt to simply to wade across the Scheldt and take Oudenaarde from that position. Marlborough again ordered a forced march of his troops. This time, though, he ordered elevan thousand troops to hold the main crossing point across the Scheldt, under the command of his Quartermaster General, William Cadogan. Cadogan's force built five additional pontoon bridges to allow Marlborough to get his eighty thousand-strong army across the river, until French foragers discovered the allied presence around 09:00 AM, initiating the battle.