World War I
World War I was a global conflict of the early 20th century from 1914-1918, between the Central Powers, Germany, Austria-Hungary, the Ottoman Empire and Bulgaria, and the Allied powers, primarily Great Britain, France, Russia, and later the United States. World War I was ignited in the Balkan city of Sarajevo in June 1914 with the assassination of Archduke Franz Ferdinand, heir to the Austro-Hungarian throne, and war was declared in August. World War I was characterized by the horror of trench warfare on the Western Front and the rise of Bolshevism in the East, and millions died in the catastrophic conflict. The causes of World War I were many, including various territorial disputes, a major arms race, conflicting political ideologies, and more. World War I ended with the Treaty of Versailles; however, the agreement left many issues unresolved and heaped blame and the requirement for reparations on Germany, sowing the seeds of World War II.