In September 1939, World War II started with the invasions of Poland by Nazi Germany and the Soviet Union (as part of the Molotov–Ribbentrop Pact). More than six million Polish citizens died in the war.[15][16] In 1944, a Soviet-backed Polish provisional government was formed which, after a falsified referendum in 1947 took control of the country and Poland became a satellite state[17] of the Soviet Union, as People's Republic of Poland. During the Revolutions of 1989, Poland's Communist government was overthrown and Poland adopted a new constitution establishing itself as a democracy.