Did you know that during World War I, 1.8 million people died in Russia? That's a lot! World War I was fought between two major alliances of countries: the Allied Powers and the Central Powers.
The Allied Powers were formed as a defence against the aggression of Germany. Germany felt that this powerful alliance surrounding them posed a real threat to their existence and power in the region. Germany made an alliance with Austria-Hungary and Italy in 1881. The countries agreed to protect each other in the event they were attacked by France.
Belgium declared itself neutral at the start of the war, but later joined the Allied Powers after they were invaded by Germany.
In 1914, Italy was allied with the Central Powers, but as the war progressed they switched sides and decided to back the Allied Powers instead.
The majority of the fighting along the Western Front took place in France. The two allied countries with the most soldiers killed were Russia with 1.8 million and France with 1.4 million. The United States was never officially a member of the Allied Powers, but called itself an "Associated Power."
Allied Powers: Serbia, Russia, France, the British Empire, Italy, and Belgium.
Central Powers: Austria-Hungary, Germany, Bulgaria, and the Ottoman Empire