In the Battle of Wavre was the final major military action of the of the Hundred Days campaign and the Napoleonic Wars. It was fought on 18-19 June 1815 between the Prussian rearguard under the command of General Johann von Thielmann and three corps of the French army under the command of Marshal Grouchy. In the battle, a Prussian rearguard was pushed back by a much larger French force, but resisted for long enough for Field Marshal Blücher"s main force to move to help Wellington defeat Napoleon at Waterloo.