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
Nicholas II of Russia wife, Queen Mary. In February 1913, Nicholas presided over the tercentenary celebrations for the Romanov Dynasty. On 21 February, a "Te Deum" took place at Kazan Cathedral, and a state reception at the Winter Palace. In May, Nicholas and the imperial family made a pilgrimage across the empire, retracing the route down the Volga River that was made by the teenage Michael Romanov from the Ipatiev Monastery in Kostroma to Moscow in 1613 when he finally agreed to become tsar. On 28 June 1914 Archduke Franz Ferdinand of Austria, heir to the Austro-Hungarian throne, was assassinated by a Bosnian Serb