four o'clock
It was now nearly seven o'clock in the evening , and the Prussians were engaged at St. Lambert , Napoleon having detached Lobau 's corps to arrest their progress . Their march had been a terrible one . They had to traverse country roads softened by the rain ; the men were up to their ankles in mud , guns and carriages stuck fast , and it was not until after tremendous efforts that the leading squadron of their cavalry passed through the wood of Wavre and came in view of the battle that was raging . It was then past four o'clock , and another hour passed before any considerable number of infantry arrived . It was at this time Napoleon sent Lobau against them . He was able for a time to resist their advance ; but as fresh troops came up from the rear the Prussians began to win their way forward , and Napoleon was obliged to send two more divisions of the Young Guard to check them . He now saw that all was lost unless he could , before the whole of the Prussian army arrived , break down the resistance of the British .