Read and annotate this article. World War I, also known as the Great War, began in 1914 after the assassination of Archduke Franz Ferdinand of Austria. His murder catapulted into a war across Europe that lasted until 1918. During the conflict, Germany, Austria-Hungary, Bulgaria and the Ottoman Empire (the Central Powers) fought against Great Britain, France, Russia, Italy, Romania, Japan and the United States (the Allied Powers). Thanks to new military technologies and the horrors of trench warfare, World War I saw unprecedented levels of carnage and destruction. By the time the war was over and the Allied Powers claimed victory, more than 16 million people—soldiers and civilians alike—were dead. Archduke Franz FerdinandTensions had been brewing throughout Europe—especially in the troubled Balkan region of southeast Europe—for years before World War I actually broke out. A number of alliances involving European powers, the Ottoman Empire, Russia and other parties had existed for years, but political instability in the Balkans (particularly Bosnia, Serbia and Herzegovina) threatened to destroy these agreements. The spark that ignited World War I was struck in Sarajevo, Bosnia, where Archduke Franz Ferdinand—heir to the Austro-Hungarian Empire—was shot to death along with his wife, Sophie, by the Serbian nationalist Gavrilo Princip on June 28, 1914. Princip and other nationalists were struggling to end Austro-Hungarian rule over Bosnia and Herzegovina. The assassination of Franz Ferdinand set off a rapidly escalating chain of events: Austria-Hungary, like many countries around the world, blamed the Serbian government for the attack and hoped to use the incident as justification for settling the question of Serbian nationalism once and for all.