The World War II era covers the years around 1939 to 1945. It includes the events before, during, and immediately after the war. This was a global conflict involving countries across Europe, Africa, and Asia.

Major events included large battles, the Holocaust, and the use of atomic bombs in 1945. Military operations such as D-Day in 1944 helped shape the outcome of the war. Many nations contributed soldiers and resources.

The war ended in 1945 with the defeat of Axis powers. After the war, countries worked to rebuild and form new agreements. The United Nations was created to support international cooperation.