Background
Napoleon's Abdication
Napoleon signs his abdication at Fountainbleau, 1814
After 22 years of war with the rest of Europe, during which time he marched into practically every capital city, Napoleon finally surrendered to the allies in 1814. France had been invaded from four sides by the British, Austrians, Russians and Prussians and the mighty Grande Armee, which had long been the terror of mainland Europe, was a mere shadow of its former glory. The main reason for this was the disastrous invasion of Russia in 1812. Napoleon had discovered, as Hitler would do over 100 years later, that a successful invasion of Russia is almost impossible due to the sheer expanse of land that must be traversed. The result for Napoleon was that his army of 1814 comprised raw recruits and conscripts. All seemed lost and Napoleon abdicated. On 30th May of that year, the Treaty of Paris was signed between France and the Allies, restoring the Bourbon King Louis XVIII to the throne.
Escape From Elba
When Napoleon abdicated, he was exiled to the island of Elba, lying off the coast of Italy. This exile was short lived and he promptly escaped, landing in the South of France on 1st March 1815. His first encounter was with the 5th Line Regiment, led by Ney, one of his erstwhile marshals, now representing the King. These troops, sent to capture Napoleon, immediately flocked to his side. This action was widely repeated throughout the French army and within a month, Napoleon had around 200,000 men under his command again. This included many of his experienced troops of previous campaigns who were available again after returning from the various prison camps and military hospitals around Europe. Of his old generals and marshals, most of whom had accepted commissions in the Royal Army, only a handful were both willing and able to return to their old master. This lack of quality available leadership was to plague Napoleon throughout the campaign. Nevertheless, Napoleon set about moulding his available resources into a powerful enough force to pre-empt his enemies and crush the alliance of Britain, Prussia, Austria and Russia who were slowly reacting to the news of his return.