World War I, previously known as the Great War, took place from July 28, 1914 until November 11, 1918. Although it was mostly concentrated in Europe, it involved all of the world’s great powers, many of which were spread all over the world. By the end of the war, four major world empires (German, Russian, Austro-Hungarian, and Ottoman) were defeated and dismantled. The winning countries formed the League of Nations to try to prevent a recurrence of such a war, but the restrictions imposed by the Treaty of Versailles on the defeated countries eventually led to World War II.
