Serbian Campaign of World War I Serbia, Montenegro, and Greece. When Bulgaria attacked both Serbia and Greece on 16 June 1913, it lost most of its Macedonian region to those countries, and additionally the Southern Dobruja region to Romania and Adrianople (the present-day city of Edirne) to Turkey in the 33-day Second Balkan War, which further destabilized the region. On 28 June 1914, Gavrilo Princip, a Bosnian Serb student and member of a multi-ethnic organisation of national revolutionaries called Young Bosnia, assassinated Archduke Franz Ferdinand of Austria, the heir to the Austro-Hungarian throne, in Sarajevo, Bosnia. The political objective of the assassination was the independence of
Archduke Ferdinand Karl of Austria the emperor's knowledge or consent, having eloped two years before the marriage was revealed publicly. On 6 August 1911 he renounced his rights and titles as a dynast of the House of Habsburg and assumed the name of "Ferdinand Burg", at the demand of Emperor Franz Joseph. Henceforth he absented himself from the Viennese court and lived in Tyrol. By then Ferdinand Karl was suffering from tuberculosis, of which he died in 1915. He and his wife had no children. Archduke Ferdinand Karl of Austria Archduke Ferdinand Karl of Austria, later known as Ferdinand Burg (Ferdinand Carl Ludwig Joseph Johann