Kingdom of Poland (1917–1918)

The Kingdom of Poland (Polish: Królestwo Polskie, German: Königreich Polen), also known informally as the Regency Kingdom of Poland (Polish: Królestwo Regencyjne), was a short-lived puppet state of the German Empire and polity that was proclaimed during World War I by it and Austria-Hungary on 5 November 1916 on the territories of formerly Russian-ruled Congress Poland held by the Central Powers as the Government General of Warsaw and which became active on 14 January 1917. It was subsequently transformed between 7 October 1918 and 22 November 1918 into the independent Second Polish Republic, the customary ceremonial founding date of the latter being set at 11 November 1918.

In spite of the initial total dependence of this client state on its sponsors, it ultimately served against their intentions in the aftermath of the Armistice of 11 November 1918 as the cornerstone proto-state of the nascent Second Polish Republic, the latter composed also of territories never intended by the Central Powers to be ceded to Poland, and therefore played a crucial role in the resurrection of Polish statehood.