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
Archduke Franz Ferdinand of Austria themselves after him. Archduke Franz Ferdinand of Austria Archduke Franz Ferdinand, Archduke of Austria-Este (Franz Ferdinand Carl Ludwig Joseph Maria; 18 December 1863 – 28 June 1914) was a member of the imperial Habsburg dynasty, and from 1896 until his death the heir presumptive ("Thronfolger") to the Austro-Hungarian throne. His assassination in Sarajevo precipitated Austria-Hungary's declaration of war against Serbia, which in turn triggered a series of events that resulted in Austria-Hungary's allies and Serbia's declaring war on each other, starting World War I. Franz Ferdinand was born in Graz, Austria, the eldest son of Archduke Karl Ludwig of Austria