[1][2]Fourth Partition of Poland—aftermath of the The Nazi-Soviet Pact; division of Polish territories in the years 1939–1941[3][4]Beginning of Lebensraum, the Nazi German expulsion of Poles from central Poland, 1939[5][6]Operation Tannenberg, 20 October 1939, mass murder of Polish townsmen in western PolandChanges in administration of Polish territories following the German invasion of Soviet Union in 1941. The map shows the state as of 1944[7][8]German map of the "General Government", 1943The occupation of Poland by Nazi Germany and the Soviet Union during the Second World War (1939–1945) began with invasion of Poland in September 1939, and formally concluded with the defeat of Nazism by the Four Powers in May 1945. Throughout the entire course of foreign occupation the territory of Pola