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 Friedrich, Duke of Teschen of the ruling house, Friedrich adopted a military career, and served creditably for many years as commandant of the V. (Pressburg) Corps. Subsequently, commander-in-chief of the Austrian Landwehr (militia) and army inspector, he became, after the murder of the heir to the throne, Archduke Franz Ferdinand, inspector-general of the Austro-Hungarian Army. In World War I, he was —from the dynastic point of view —as grandson of the victor of Aspern, Archduke Charles, and as nephew of the victor of Custoza, Archduke Albert, the predestined head of the armed forces of Austria-Hungary; and on 11 July 1914 Friedrich was appointed supreme