World War One-The First Great War
World War I (WWI) was a global war centered in Europe that began on 28 July 1914 and lasted until 11 November 1918. It was predominantly called the World War or the Great War from its occurrence until the start of World War 2 in 1939, and the First World War or World War I thereafter. Long-term causes of the war included the imperialistic foreign policies of the great powers of Europe, including the German Empire, the Austria-Hungarian Empire, the Ottoman Empire, the Russian Empire, the British Empire, the French Republic, and Italy. The assassination on 28 June 1914 of Archduke Franz Ferdinand of Austria, the heir to the throne of Austria-Hungary, by a Yugoslav nationalist in Sarajevo, Bosnia was the proximate trigger of the war. It resulted in a Habsburg ultimatum against the Kingdom of Serbia.Several alliances formed over the previous decades were invoked, so, within weeks, the major powers were at war; via their colonies, the conflict soon spread around the world.