The Treaty of Versailles was one of five treaties that were signed at the Paris Peace Conference in 1919 that ended World War I (1914-1918). It was signed by representatives from Germany and its allies, including Austria-Hungary, Bulgaria, and Turkey; and by representatives from the Allied countries: France, Italy, Japan, Belgium, Serbia and the United Kingdom. Russia did not sign any of these treaties because it had been removed from power by a revolution led by Vladimir Lenin.
The treaty contained many provisions regarding Germany’s future military strength and limits on its military actions. It also required that Germany accept responsibility for starting World War 1; make war reparations payments to some countries who had suffered losses during the war; limit its armed forces’ strength; allow Allied troops to occupy key areas along Germany’s border; and surrender control over much of its territory in Europe (which became known as “ceded territories”). Germany could not have an army larger than 100,000 men. Other countries were given control over parts of Germany’s colonies, including Togoland, Cameroon, New Guinea and parts of Samoa and Micronesia.
The Treaty of Versailles was part of the conditions that led to World War 2 because it humiliated Germany by making them surrender territory and take responsibility for starting WW1. This caused many Germans to become very angry with their government and believe they had been treated unfairly by the rest of Europe.