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 of Franz Joseph and Maximilian) and of his second wife, Princess Maria Annunciata of Bourbon-Two Sicilies. In 1875, when he was only eleven years old, his cousin Francis V, Duke of Modena died, naming Franz Ferdinand his heir on condition that he add the name "Este" to his own. Franz Ferdinand thus became one of the wealthiest men in Austria. In 1889, Franz Ferdinand's life changed dramatically. His cousin Crown Prince Rudolf committed suicide at his hunting lodge in Mayerling. This left Franz Ferdinand's father, Karl Ludwig, as first in line to the throne. Karl Ludwig died of typhoid fever