During World War II, Poland was occupied by Nazi Germany and the Soviet Union (and Slovakia) following the invasion in September 1939, and it was formally concluded with the defeat of Germany by the Allies in May 1945. Throughout the entire course of the occupation, the territory of Poland was divided between Nazi Germany and the Soviet Union (USSR), both of which intended to eradicate Poland's culture and subjugate its people. In the summer-autumn of 1941, the lands which were annexed by the Soviets were overrun by Germany in the course of the initially successful German attack on the USSR. After a few years of fighting, the Red Army drove the German forces out of the USSR and crossed into Poland from the rest of Central and Eastern Europe.
Sociologist Tadeusz Piotrowski argues that both occupying powers were hostile to the existence of Poland's sovereignty, people, and the culture and aimed to destroy them. Before Operation Barbarossa, Germany and the Soviet Union coordinated their Poland-related policies, most visibly in the four Gestapo–NKVD conferences, where the occupiers discussed their plans to deal with the Polish resistance movement.
