The Battle of France, also known as the Western Campaign, the French Campaign and the Fall of France, during the Second World War, was the German invasion of France, that notably introduced tactics that are still used. France and the Low Countries were conquered, ending land operations on the Western Front until the Normandy landings on 6 June 1944.

World War II or the Second World War was a global conflict between two major alliances: the Allies and the Axis powers. The vast majority of the world's countries, including all the great powers, fought as part of these military alliances. Many participating countries invested all available economic, industrial, and scientific capabilities into the war, blurring the distinction between civilian and military resources. Aircraft played a major role, enabling the strategic bombing of population centres and delivery of the only two nuclear weapons ever used in war. It was by far the deadliest conflict in history, resulting in 70–85 million fatalities. Millions died due to genocides, including the Holocaust, as well as starvation, massacres, and disease. In the wake of Axis defeat, Germany, Austria, and Japan were occupied, and war crime tribunals were conducted against German and Japanese leaders.