World War One or "The Great War" as it became known, occurred due to many causes, some of which still remain unexposed today. The obvious trigger for the war was the assassination of the heir to the Austro-Hungarian throne, the Archduke Franz Ferdinand and his wife Sophie on 28th June 1914. The assassination occurred during the Archduke's visit to Sarajevo, the capital of Bosnia and Herzegovina. The Archduke was targeted due to the general feeling amongst Serbians that, once appointed to the throne, Ferdinand would continue the persecution of Serbs living within the borders of the Austro-Hungarian Empire. Just moments after the two had been shot; authorities arrested the culprit, Gavrilo Princip, a Serbian student, who was believed to have been linked to the Serbian terrorist organization, The Black Hand. .
Causes of the war also dealt with such ideologies as Nationalism, Imperialism and militarism along with the prominent alliance systems in Europe all strongly affected the outbreak of the war. All of these factors where established in many of Europe's "Great Powers" which consisted of Great Britain, France, Germany, Austria-Hungary and Russia. .
During the late nineteenth and into the twentieth centuries, Nationalism was a prominent movement that had spread itself across Europe. All major powers had strong feelings toward the concepts of supporting their own nation. Nationalists believed that their own nation's needs must be met before that of other nations. These strong beliefs sometimes became obsessive as nationalists became so proud of their nation that they strived for it to become richer and more powerful than any other. .
This wave of national pride became a major problem for the Austro-Hungarian Empire as they attempted to maintain a form of order and control within the annexed area of Bosnia. This power was placed under threat due to the Slavonic peoples dislike of their Austro-Hungarian superiors and there desire to attach themselves to Serbia and create an independent state to be known as Yugoslavia, or "The Land of the South Slavs.