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 Felix of Austria Archduke Felix of Austria Archduke Felix of Austria (given names: "Felix Friedrich August Maria vom Siege Franz Joseph Peter Karl Anton Robert Otto Pius Michael Benedikt Sebastian Ignatius Marcus d'Aviano"; 31 May 1916 – 6 September 2011) was the last surviving child of the last Austrian Emperor Charles I and a member of the House of Habsburg. He was a younger brother of former Crown Prince Otto of Austria, who predeceased Felix by two months. Archduke Felix was born in the Schönbrunn Palace in Vienna the third son of the then heir presumptive to the throne of Austria-Hungary the Archduke