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 Ferdinand Karl of Austria the emperor's knowledge or consent, having eloped two years before the marriage was revealed publicly. On 6 August 1911 he renounced his rights and titles as a dynast of the House of Habsburg and assumed the name of "Ferdinand Burg", at the demand of Emperor Franz Joseph. Henceforth he absented himself from the Viennese court and lived in Tyrol. By then Ferdinand Karl was suffering from tuberculosis, of which he died in 1915. He and his wife had no children. Archduke Ferdinand Karl of Austria Archduke Ferdinand Karl of Austria, later known as Ferdinand Burg (Ferdinand Carl Ludwig Joseph Johann