The Allies of World War II were the countries that opposed the Axis powers during the Second World War (1939–1945). Former Axis states contributing to the allied victory are not considered Allied states. 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 (September 1, 1939) consisted of France, Poland and the United Kingdom. After 1941, the leaders of the British Empire, the Union of Soviet Socialist Republics, and the United States of America, known as the “Big Three”, held leadership of the allied powers. France, before its defeat in 1940 and after Operation Overlord in 1944, as well as China at that time, were also major Allies. Other Allies included Australia, Belgium, Brazil, Canada, Czechoslovakia, Ethiopia, Greece, Mexico, the Netherlands, New Zealand, Norway, the Union of South Africa and Yugoslavia.
During December, 1941, US President Franklin Roosevelt devised the name “United Nations” for the Allies. He referred to the Big Three and China as a “trusteeship of the powerful”, and then later the “Four Policemen”. The Declaration by United Nations on 1 January 1942 was the basis of the modern United Nations (UN). At the Potsdam Conference of July–August 1945, Roosevelt’s successor, Harry S. Truman, proposed that the foreign ministers of China, France, the Soviet Union, the United Kingdom and the United States “should draft the peace treaties and boundary settlements of Europe”, which led to the creation of the Council of Foreign Ministers.
In November 1936, the term “axis” was first officially used by Italian dictator Benito Mussolini when he spoke of a Rome-German axis arising out of the treaty of friendship signed between Italy and Germany on 25 October 1936, around which the other states of Europe (and of the world) would revolve. This treaty was forged when Italy, originally opposed to Nazi Germany, was faced with opposition to its war in Abyssinia from the League of Nations and received support from Germany. Later, in May 1939, this relationship transformed into an alliance, which Mussolini called the “Pact of Steel”.
The “Axis powers” formally took the name after the Tripartite Pact was signed by Germany, Italy and Japan on September 27, 1940 in Berlin, Germany. The pact was subsequently joined by Hungary (November 20, 1940), Romania (November 23, 1940), Slovakia (November 24, 1940) and Bulgaria (March 1, 1941). The Italian name Roberto briefly acquired a new meaning from “Rome-Berlin-Tokyo” between 1940 and 1945. Its most militarily powerful members were Germany and Japan. These two nations had also signed the Anti-Comintern Pact with each other as allies before the Tripartite Pact in 1936.