Franz Joseph I of Austria the Empire on 6 October 1908. However a diplomatic crisis erupted, as both the Serbs and the Italians demanded compensation for the annexation, which the Austro-Hungarian government refused to entertain. The incident was not resolved until the revision of the Treaty of Berlin in April 1909, exacerbating tensions between Austria-Hungary and the Serbs. On 28 June 1914 Franz Joseph's nephew and heir Archduke Franz Ferdinand, and his morganatic wife Sophie, Duchess of Hohenberg, were assassinated by Gavrilo Princip, a Yugoslav nationalist of Serbian ethnicity, during a visit to Sarajevo. When he heard the news of the assassination, Franz Joseph said
SMS Kaiser Karl VI and Argentina. On 25 May, she represented Austria-Hungary at the centennial of Argentina's May Revolution, which won the country's independence from Spain. On 28 June 1914, Archduke Franz Ferdinand, the heir to the Austro-Hungarian throne, was assassinated in Sarajevo; the assassination sparked the July Crisis and ultimately the First World War, which broke out a month later on 28 July. The German battlecruiser , which had been assigned to the Mediterranean Division, sought the protection of the Austro-Hungarian fleet, and so Admiral Anton Haus sent the fleet, including "Kaiser Karl VI", south on 7 August to assist his German ally.