World War I

World War I (1914—1918) was the first global conflict, pitting the Central Powers (Germany, Austria-Hungary, the Ottomans, Bulgaria) against the Entente (France, Britain, Russia, Italy, the USA). It began with the assassination of Archduke Franz Ferdinand in Sarajevo and turned into trench bloodletting with millions of casualties and new weapons — gas, tanks, aircraft. Four empires collapsed; the Treaty of Versailles redrew Europe but planted the contradictions that led to World War II twenty years later.