Which nations were members of the "Big Four" allied powers of World War I?

The Big Four refer to the four top Allied powers of World War I and their leaders who met at the Paris Peace Conference in 1919. The nations were Great Britain, France, Italy and the United States of America. The representing leaders were British Prime Minister David Lloyd-George, French Premier Georges Clemenceau, Italian Prime Minister Vittorio Orlando and U.S. President Woodrow Wilson.

These four nations were the principal allied combatants during the war, contributing millions of soldiers, munitions and industrial production to the war effort. Russia was not included since the Russian Revolution and their subsequent peace treaty with Germany removed them from the conflict.

The Big Four (also referred to as the Council of Four) were the primary architects of the Treaty of Versailles, which was the treaty to end the war with Germany, and the other treaties to end the war with the other members of the Central Powers (Austria-Hungary, Ottoman Turkey and Bulgaria).