Separated from his wife and son, who had come under Austrian control, cut off from the allowance guaranteed to him by the Treaty of Fontainebleau, and aware of rumours he was about to be banished to a remote island in the Atlantic Ocean, Napoleon escaped from Elba on 26 February 1815. He landed at Golfe Juan on the French mainland, two days later The 5th Regiment was sent to intercept him and made contact just south of Grenoble on 7 March 1815. Napoleon approached the regiment alone, dismounted his horse and, when he was within gunshot range, shouted, "Here I am. Kill your Emperor, if you wish.”The soldiers responded with, "Vive L'Empereur!" and marched with Napoleon to Paris; Louis XVIII fled. On 13 March, the powers at the Congress of Vienna declared Napoleon an outlaw, and four days later Great Britain, the Netherlands, Russia, Austria and Prussia bound themselves to put 150,000 men into the field to end his rule.
Napoleon arrived in Paris on 20 March and governed for a period now called the Hundred Days. By the start of June the armed forces available to him had reached 200,000, and he decided to go on the offensive to attempt to drive a wedge between the oncoming British and Prussian armies. The French Army of the North crossed the frontier into the United Kingdom of the Netherlands, in modern-day Belgium.
Napoleon's forces fought the allies, led by Wellington and Gebhard Leberecht von Blücher, at the Battle of Waterloo on 18 June 1815. Wellington's army withstood repeated attacks by the French and drove them from the field while the Prussians arrived in force and broke through Napoleon's right flank. Napoleon's was defeated because he had to fight two armies with one, attacking an army in an excellent defensive position through wet and muddy terrain. His health that day may have affected his presence and vigour on the field, added to the fact that his subordinates may have let him down. Despite this, Napoleon came very close to clinching victory. Outnumbered, the French army left the battlefield in disorder, which allowed Coalition forces to enter France and restore Louis XVIII to the French throne.