German School, (19th century). Medium: engraving. Date: 1872. William I,also known as Wilhelm I (22 March 1797 ? 9 March 1888), of the House of Hohenzollern was the King of Prussia (2 January 1861 ? 9 March 1888) and the first German Emperor (18 January 1871 ? 9 March 1888). Under the leadership of William and his Minister President Otto von Bismarck, Prussia achieved the unification of Germany and the establishment of the German Empire. Provenance: Private Collection. Photographic rights held by The Bridgeman Art Library.