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
Archduchess Elisabeth Amalie of Austria Saxony, he had no children. With his second wife Princess Maria Annunciata of Bourbon-Two Sicilies, Karl Ludwig fathered Archduke Franz Ferdinand of Austria, who became heir to the throne of Austria-Hungary, as well as three other siblings. Elisabeth and her older sister Archduchess Maria Annunziata of Austria (later Abbess of the Theresia Convent in the Hradschin, Prague) were the product of his third marriage to Infanta Maria Theresa of Portugal, a daughter of the deposed King Miguel I of Portugal. In addition, her father was a younger brother of Franz Joseph I of Austria, the reigning emperor at the time