Allies of World War II
The Allies of World War II were a group of countries that together opposed the Axis powers during the Second World War (1939–1945). The Allies promoted the alliance as a means to defeat Nazi Germany, the Empire of Japan, Fascist Italy and their allies.
At the start of the war on 1 September 1939, the Allies consisted of Poland, the United Kingdom, and France as well as their dependent states, such as British India. They were joined by the independent Dominions of the British Commonwealth: Canada, Australia, New Zealand and South Africa. After the start of the German invasion of North Europe until the Balkan Campaign, the Netherlands, Belgium, Greece, and Yugoslavia joined the Allies. After first having cooperated with Germany in invading Poland whilst remaining neutral in the Allied-Axis conflict, the Soviet Union perforce joined the Allies in June 1941 after being invaded by Germany. The United States provided war materiel and money to the Allies all along, and officially joined in December 1941 after the Japanese attack on Pearl Harbor. China had already been in a prolonged war with Japan since the Marco Polo Bridge Incident of 1937 and officially joined the Allies in December 1941.
The Big Three—the United Kingdom, the Soviet Union, and the United States—formed a Grand Alliance that was key to victory. They controlled Allied strategy; relations between the United Kingdom and the United States were especially close. The alliance was formalized by the Declaration by United Nations, on 1 January 1942. The Big Three together with China were referred to as a "trusteeship of the powerful", then were recognized as the "Four Powers" in the Declaration by United Nations and later as the "Four Policemen" of the United Nations.
After the war ended, the Allied states became the basis of the modern United Nations.