Article 231 of the Treaty of Versailles

Article 231, often known as the war guilt clause (German: Kriegsschuldklausel), was the opening article of the reparations section of the Treaty of Versailles, which ended the First World War between the German Empire and the Allied and Associated Powers. The article did not use the word guilt but it served as a legal basis under which Germany was to pay reparations for damages caused during the war.

Source: Wikipedia — Article 231 of the Treaty of Versailles (CC BY-SA 4.0)