World War II starts by Nazi Germany invading Poland. Poland surrendered .
September 27, 1940
Germany invades Belgium, the Netherlands Luxembourg, and France. After a few weeks, France is the only country that didn't surrender.
June 22, 1941
Germany begins their bombing raid against Great Britain in the Battle of Britain.
December 7, 1941
Germany, Italy, and Japan make and sign the Tripartite Pact in Berlin to ring together an alliance called the Axis powers. If any of these countries get attacked, they will fight alongside one another.
In the largest German military effort of WWII, Germany launches Operation Barbarossa, the invasion of the Soviet Union. The Soviet Union formally joined the Allied nations a few weeks later.
Japan launches a surprise attack on American and bombed Hawaii's naval base at Pearl Harbor on the island of Oahu.