At Wavre, the Prussian IV Corps under Bülow was designated to lead the march to Waterloo as it was in the best shape, not having been involved in the Battle of Ligny. Although they had not taken casualties, IV Corps had been marching for two days, covering the retreat of the three other corps of the Prussian army from the battlefield of Ligny. They had been posted farthest away from the battlefield, and progress was very slow.

The roads were in poor condition after the night's heavy rain, and Bülow's men had to pass through the congested streets of Wavre and move 88 artillery pieces. Matters were not helped when a fire broke out in Wavre, blocking several streets along Bülow's intended route. As a result, the last part of the corps left at 10:00, six hours after the leading elements had moved out towards Waterloo. Bülow's men were followed to Waterloo first by I Corps and then by II Corps.