The imperial conflict known as World War I lasted from 1914 until 1918 and involved many of the world's great powers divided into the Allies, including France, Britain, Russia, and later the United States, and the Central Powers, primarily Germany, Austria-Hungary, and the Ottoman Empire. The war began after the assassination of Archduke Franz Ferdinand of Austria and was characterized by trench warfare, massive military engagements, and extensive loss of life. The conflict ended with the signing of the Treaty of Versailles in 1919, which imposed heavy reparations on Germany and redrew national boundaries, setting the stage for future geopolitical tensions.