World War I was fought between two major alliances of countries: the Allied Powers and the Central Powers. The Allied Powers were largely formed as a defense against the aggression of Germany and the Central Powers. They were also known as the Entente Powers because they began as an alliance between France, Britain, and Russia called the Triple Entente.
France - Germany declared war on France on August 3, 1914. France had been preparing for war after Germany and Russia went to war. The majority of the fighting along the Western Front took place inside of France.
Britain - Britain entered the war when Germany invaded Belgium. They declared war on Germany on August 4, 1914. British troops joined French troops on the Western Front to stop the advance of Germany across Western Europe.
Russia - The Russian Empire was an early entry into the war. Germany declared war on Russia on July 31, 1914. They expected that Russia would defend Serbia against the invasion of Serbia by Germany's ally Austria-Hungary. The Russian Empire also included Poland and Finland. After the Russian Revolution, Russia left the Allied Powers and signed a peace treaty with Germany on March 3, 1918.
United States - The United States tried to remain neutral during the war. However, it entered the war on the side of the Allied Powers on April 6, 1917 when it declared war on Germany. Around 4,355,000 American troops were mobilized during the war with around 116,000 losing their lives.
Other Allied countries included Japan, Italy, Belgium, Brazil, Greece, Montenegro, Romania, and Serbia.
David Lloyd George by Harris and Ewing
Nicholas II from the Bain News Service
France: Georges Clemenceau - Clemenceau was Prime Minister of France from 1917 to 1920. His leadership helped hold France together during the most difficult times of the war. His nickname was "The Tiger." Clemenceau represented the French at the peace talks and advocated for harsh punishment for Germany.
Britain: David Lloyd George - Lloyd George was the Prime Minister of Britain during much of the war. He was an advocate of Britain entering the war and kept the country together during the war.
Britain: King George V - King of Britain during the war, George V was a figurehead with little power, but often visited the front to inspire the British troops.
Russia: Tsar Nicolas II - Tsar Nicholas II was leader of Russia at the start of World War I. He entered the war in defense of Serbia. However, the war effort was disastrous in the eyes of the Russian people. The Russian Revolution occurred in 1917 and Nicolas II was removed from power. He was executed in 1918.
United States: President Woodrow Wilson - President Woodrow Wilson was re-elected on the platform that he kept America out of the war. However, he was given little choice and declared war on Germany in 1917. After the war, Wilson advocated less harsh terms on Germany, knowing that a healthy German economy would be important for all of Europe.
Douglas Haig by Unknown
Ferdinand Foch by Ray Mentzer
John Pershing from the Bain News Service
France: Marshall Ferdinand Foch, Joseph Joffre, Robert Nivelle
Britain: Douglas Haig, John Jellicoe, Herbert Kitchener
Russia: Aleksey Brusilov, Alexander Samsonov, Nikolai Ivanov
United States: General John J. Pershing
Interesting Facts about the Allied Powers
Belgium declared itself as neutral at the start of the war, but joined the Allies after they were invaded by Germany.
It is estimated that around 42 million military personnel were mobilized by the Allies during the war. Around 5,541,000 were killed in action and another 12,925,000 were wounded.
The two Allied countries with the most soldiers killed were Russia with 1,800,000 and France with around 1,400,000.
Vladimir Lenin became the leader of Soviet Russia after Tsar Nicholas II was overthrown during the Russian Revolution. Lenin wanted Russia out of the war, so he made peace with Germany.
The United States was never an official member of the Allies, but called itself an "Associated Power."