Granted sovereignty there by the Allied powers, Napoleon governed Elba with characteristic energy, overseeing construction, agricultural and mining projects. Tourists and travellers went out of their way to see the fallen Emperor play ‘parish politics’ on the little island. But Napoleon was frustrated, and nervous about rumours of further restraints on his actions. In retrospect, it is hard to account for the widespread surprise at what happened next.

Late in February 1815, Napoleon sailed for France at the head of a thousand soldiers. ‘The Devil is unchained’ wrote the British Commissioner on Elba. This was a characteristic, high-stakes gamble, and despite many misgivings in every section of French society, the gamble paid off. Regiment after regiment deserted the king. In just twenty-three days, Napoleon returned to Paris and took back the throne. Louis XVIII, his family and many in his court fled to the Netherlands. Those who remained made their peace with the Emperor.

Russia, Austria, Prussia, Britain and their allies formed a new coalition, pledging to put vast armies in the field to force Napoleon from his throne.