What year were the allies formed?

The Allies, primarily composed of the United Kingdom, the Soviet Union, the United States, and China, were formed during World War II. The alliance solidified in 1941 after the U.S. entered the war following the attack on Pearl Harbor, although cooperation among the Allies began earlier, notably with the signing of the Atlantic Charter in August 1941. The formal declaration of unity among these nations occurred as they sought to oppose the Axis powers.