Invasion of Poland – 1 september 1939
The invasion of Poland (1 September – 6 October 1939), also known as the September campaign (Polish: kampania wrześniowa), 1939 defensive war (Polish: wojna obronna 1939 roku) and Poland campaign (German: Überfall auf Polen, Polenfeldzug), was a joint attack on the Republic of Poland by Nazi Germany and the Soviet Union which marked the beginning of World War II. The German invasion began on 1 September 1939, one week after the signing of the Molotov–Ribbentrop