The World War II expulsions took place within two specific political entities established by the Nazis, divided from each other by a closed border: one area outright annexed to the Reich in 1939–1941, and another called the General Government, a precursor to the further expansion of the German administrative settlement area. Eventually, as Adolf Hitler explained in March 1941, the General Government would be cleared of all Poles and the region turned into a "purely German area" within 15–20 years, and in place of 15 million Poles, 4–5 million Germans would live there.