Bulgaria during World War I 28 June 1914, Gavrilo Princip, a Bosnian-Serb student and member of Young Bosnia, assassinated the heir to the Austro-Hungarian throne, the Archduke Franz Ferdinand of Austria in Sarajevo, Bosnia. This began a period of diplomatic manoeuvring between Austria-Hungary, Germany, Russia, France and Britain called the July Crisis. Wanting to end Serbian interference in Bosnia conclusively, Austria-Hungary delivered the July Ultimatum to Serbia, a series of ten demands that were intentionally meant to be unacceptable in order to precipitate a war with Serbia. When Serbia acceded to only eight of the ten demands levied against it in the ultimatum, Austria-Hungary declared
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