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 Franz Ferdinand of Austria Duke of Teschen. Franz began to visit Archduke Friedrich's villa in Pressburg (now Bratislava), and in turn Sophie wrote to Franz Ferdinand during his convalescence from tuberculosis on the island of Lošinj in the Adriatic. They kept their relationship a secret, until it was discovered by Isabella herself. To be eligible to marry a member of the imperial House of Habsburg, one had to be a member of one of the reigning or formerly reigning dynasties of Europe. The Choteks were not one of these families, although they did include among their ancestors, in the female line, princes of Baden,