Napoleon planned to attack them separately, before they could link up and invade France with other members of the coalition. Wellington's and Blücher's armies were cantoned close to the northeastern border of France. Upon Napoleon's return to power in March 1815 (beginning the Hundred Days), many states that had previously opposed him formed the Seventh Coalition and hurriedly mobilised their armies. The battle was known contemporarily as the Battle of Mont Saint-Jean in France or La Belle Alliance ('the Beautiful Alliance') in Prussia. The other comprised three corps of the Prussian army under Field Marshal von Blücher (the fourth corps of this army fought at the Battle of Wavre on the same day). One of these was a British-led force with units from the United Kingdom, the Netherlands, Hanover, Brunswick, and Nassau, under the command of the Duke of Wellington (often referred to as the Anglo-allied army or Wellington's army). A French army under the command of Napoleon was defeated by two armies of the Seventh Coalition. The Battle of Waterloo ( Dutch pronunciation: ⓘ) was fought on Sunday 18 June 1815, near Waterloo (at that time in the United Kingdom of the Netherlands, now in Belgium), marking the end of the Napoleonic Wars.