The Waterloo campaign (15 June – 8 July 1815) was fought between the French Army of the North and two Seventh Coalition armies, an Anglo-allied army and a Prussian army. Initially the French army was commanded by Napoleon Bonaparte, but he left for Paris after the French defeat at the Battle of Waterloo. Command then rested on Marshals Soult and Grouchy, who were in turn replaced by Marshal Davout, who took command at the request of the French Provisional Government. The Anglo-allied army was commanded by the Duke of Wellington and the Prussian army by Prince Blücher. The war between France and the Seventh Coalition came when the other European Great Powers refused to recognise Napoleon as Emperor of the French upon his return from exile on the island of Elba, and declared war on him, rather than France, as they still recognised Louis XVIII as the king of France and considered Napoleon a usurper. Rather than wait for the Coalition to invade France, Napoleon decided to attack his enemies and hope to defeat them in detail before they could launch their combined and coordinated invasion. He chose to launch his first attack against the two Coalition armies cantoned in modern-day Belgium, then part of the newly formed United Kingdom of the Netherlands, but until the year before part of the First French Empire. Hostilities started on 15 June when the French drove in the Prussian outposts and crossed the river Sambre at Charleroi placing their forces between the cantonment areas of Wellington's Army (to the west) and Blücher's army to the east. On 16 June the French prevailed with Marshal Ney commanding the left wing of the French army holding Wellington at the Battle of Quatre Bras and Napoleon defeating Blücher at the Battle of Ligny. On 17 June, Napoleon left Grouchy with the right wing of the French army to pursue the Prussians while he took the reserves and command of the left wing of the army to pursue Wellington towards Brussels. On the night of 17 June the Anglo-allied army turned and prepared for battle on a gentle escarpment, about south of the village of Waterloo. The next day the Battle of Waterloo proved to be the decisive battle of the campaign. The Anglo-allied army stood fast against repeated French attacks, until with the aid of several Prussian corps that arrived at the east side of the