Wilhelm I of Germany is proclaimed Kaiser Wilhelm in the Hall of Mirrors of the Palace of Versailles (France) towards the end of the Franco-Prussian War. Wilhelm already had the title of German Emperor since the constitution of 1 January 1871, but he had hesitated to accept the title.

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 regent of Prussia from 1858 to 1861 for his elder brother, King Frederick William IV. During the reign of…