World War II was the deadliest military conflict in history.

The Allies, formally referred to as the United Nations from 1942, were an international military coalition formed during World War II to oppose the Axis powers.

Almost every country in the world participated in World War II.

The final battles of the European theatre of World War II continued after the definitive surrender of Nazi Germany to the Allies, signed by Field Marshal Wilhelm Keitel on 8 May 1945 (VE Day) in Karlshorst, Berlin.

The Allied bombing of Hamburg during World War II included numerous attacks on civilians and civic infrastructure.

The aftermath of World War II saw the rise of two superpowers, the Soviet Union and the United States.