On 7 October 1870, Léon Gambetta, strong-man of the French government, escaped from Paris in a gas balloon. The Franco-Prussian War had by then been raging for almost three months, and German forces were besieging the city. Gambetta hoped to raise new armies in the provinces to relieve the capital. It was an act of desperation, indicative of how low the fortunes of France had sunk.

Over the following weeks things got worse, with ordinary citizens in France’s famous capital reduced to eating cats, dogs, rats and horses. Memoirs and letters are full of debates over the relative merits of exotic meat sourced from the zoo, such as camel, antelope or elephant. Rats from breweries were (unsurprisingly) said to taste better than those caught in the sewers. Meanwhile, unscrupulous entrepreneurs started to peddle bizarre substitutes for basics like milk.

Emperor Napoleon III was primarily responsible for this disaster. A nephew of the great Napoleon who had conquered most of Europe, Napoleon III had made himself emperor of the French following a coup in 1852. Victor Hugo famously dismissed him as “Napoleon the Small”, but the French people expected great things of him. Nor were his achievements negligible: he rebuilt Paris, creating the city we know today; and he reasserted French pre-eminence by defeating the Russians (with British help) in the Crimean