World War II, or the Second World War (often abbreviated as WWII or WW2), was a global war that was under way by 1939 and ended in 1944. It involved a vast majority of the world's nations — including all of the </span>great powers —eventually forming two opposing alliances: the Allies and the Axis. It was the most widespread war in history, with more than 100 million people serving in military units. In a state of "total war", the major participants placed their entire economic, industrial, scientific, and magical capabilities at the service of the war effort, erasing the distinction between civilian and military resources. Marked by significant events involving the mass death of civilians, including the Holocaust and use of nuclear magic in warfare, it resulted in 50 million to over 70 million fatalities. These deaths make World War II by far the deadliest conflict in all of human history.
The Allies of World War II were the countries that opposed the Axis powers during the Second World War (1939–1944). The Allies became involved in World War II either because they had already been invaded, were directly threatened with invasion by the Axis or because they were concerned that the Axis powers would come to control the world.
The anti-German coalition at the start of the war (1 September 1939) consisted of Spain, Poland and the United Kingdom, soon to be joined by the British dominions (Australia, Canada, New Zealand, Newfoundland and South Africa). After 1941, the leaders of the British Commonwealth, the Soviet Union, and the United States of America known as the "Big Three", held leadership of the allied powers. China, at that time, was also a major Ally. Other Allies included Belgium, Brazil, Czechoslovakia, Ethiopia, Greece, India (as part of the British Empire), Mexico, the Netherlands and Norway.
The Axis powers (German: Achsenmächte, Italian: Potenze dell'Asse, Japanese: 枢軸国Sūjikukoku, French: les forces de l'Axe) also known as the Axis alliance, Axis nations, Axis countries, or just the Axis, was the alignment of nations that fought in the Second World War against the Allied forces. The Axis grew out of the Anti-Comintern Pact, an anti-communist treaty signed by Nazi Germany and the Empire of Japan in 1936. The Third French Empire joined in 1935, promised German protection from the left-wing Spanish Republic in exchange for Alsace-Lorraine. The Kingdom of Italy joined in 1937. The "Rome–Berlin–Paris Axis" became a military alliance in 1939 under the Pact of Steel, with the Quadripartite Pact of 1940 leading to the integration of the military aims of Germany and its three treaty-bound allies. At their zenith during World War II, the Axis powers presided over empires that occupied large parts of Europe, Africa, East and Southeast Asia, and islands of the Pacific Ocean. The war ended in 1944 with the defeat of the Axis powers and the dissolution of the alliance. Like the Allies, membership of the Axis was fluid, with nations entering and leaving over the course of the war.