War Begins. In the early hours of Friday, September 1, 1939, the German armies stormed across the Polish frontierwithout a declaration of war. The Free City of Danzig (the presentday city of Gdansk, Poland, which was then an independent territory) was proclaimed a German city by Nazi agitators in the city. Two days later Great Britain and France declared war on Germany.Important dates in Europe and northern Africa: 1939-1942
This World War II timeline highlights postwar events from October 1945-September 1951. The time period after the war saw a great deal of instability as relations between Russia and the Allies soured. Get information on Europe and Japan after World War II.
Japan's bombing of Pearl Harbor was the major event that caused the United States to enter World War II. On December 7, 1941, Japan bombed the harbor, which damaged 300 planes, eight battleships, and killed over 2,000 people. Learn more about the attack.