In World War I, the nations allied by treaty against Germany and the other Central Powers; originally Great Britain, France, and Russia bound by the Treaty of London (1914), later joined by Italy, Japan, and Portugal. The United States was an associated power beginning in 1917.
In World War II, the nations associated against the Axis, especially Great Britain, the Soviet Union (from June, 1941), and the United States (from December, 1941). Other chief allies were China and France (1939-1940, 1944-1945).
See: United Nations
Also called: Allied Powers