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
Trialism in Austria-Hungary and Serbs. The curiosity is that no act of Sabor dethroned king Karl I, nor did it acknowledge the entering in a state union with Serbia, which is today mentioned in the preamble of the Constitution of Croatia. Trialism in Austria-Hungary In the history of the Austria-Hungary trialism was the political movement that aimed to reorganize the bipartite Empire into a tripartite one, creating a Croatian state equal in status to Austria and Hungary. Franz Ferdinand promoted trialism before his assassination in 1914 to prevent the Empire from being ripped apart by Slavic dissent. The Empire would be restructured three