Franz Joseph I of Austria of his only son and heir, Crown Prince Rudolf, in 1889, and the assassination of his wife, Empress Elisabeth, in 1898. After the Austro-Prussian War, Austria-Hungary turned its attention to the Balkans, which was a hotspot of international tension because of conflicting interests with the Russian Empire. The Bosnian Crisis was a result of Franz Joseph's annexation of Bosnia and Herzegovina in 1908, which had been occupied by his troops since the Congress of Berlin (1878). On 28 June 1914, the assassination of his nephew, Archduke Franz Ferdinand, in Sarajevo resulted in Austria-Hungary's declaration of war against the Kingdom of
Serbian nationalism some Štokavian-speaking peoples to call themselves names other than Serbs. Ilija Garašanin was another early proponent of Serbian nationalism and a proponent of a Greater Serbia - a Serbian state whose borders were extended to include all Serbs in the Balkan region. After Serbia was recognized as an independent state in 1878, both South Slavs and the Serbian government considered their peoples in Habsburg-ruled Austria-Hungary to be under occupation resulting in increasing antagonism between Serbia and Austria-Hungary from the late 19th century to the early 20th century. In 1914 Austrian Archduke Franz Ferdinand was assassinated by Bosnian Serb revolutionary Gavrilo