German
The German Empire (German: Deutsches Kaiserreich), also referred to as Imperial Germany, the Second Reich, or simply Germany, was the period of the German Reich from the unification of Germany in 1871 until the November Revolution in 1918, when the German Reich changed its form of government from a monarchy to a republic.The empire was founded on 18 January 1871, when the south German states, except for Austria, Liechtenstein and Switzerland, joined the North German Confederation and the new constitution came into force on April 16, changing the name of the federal state to the German Empire and introducing the title of German Emperor for Wilhelm I, King of Prussia from the House of Hohenzollern.