France realised with growing unease that the eternally fragmented patchwork of German states was gradually becoming a powerful neighbour under Prussian rule. Emperor Napoleon III and Bismarck sharpened their knives. After countless provocations on both sides, war broke out in 1870. The French left the battlefield defeated, while Germany celebrated its victory, united in “blood and iron”. And as if that wasn’t enough humiliation, William I was proclaimed emperor in the Hall of Mirrors at Versailles. The German Empire was born, and the year-long animosity between the French and the Germans appeared to be sealed.