The Battle of Sedan was fought during the Franco-Prussian War from 1 to 2 September 1870. Resulting in the capture of Emperor Napoleon III and over a hundred thousand troops, it effectively decided the war in favour of Prussia and its allies, though fighting continued under a new French government.

William I, or Wilhelm I, was King of Prussia from 1861 and German Emperor from 1871 until his death in 1888. A member of the House of Hohenzollern, he was the first head of state of a united Germany. He was de facto head of state of Prussia from 1858, when he became regent for his brother Frederick William IV. During the reign of his grandson Wilhelm II, he was known as Wilhelm the Great.