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
Muhamed Mehmedbašić the way to Sarajevo, gendarmes searched the train; fearing they were on to him, he threw the knife out the window. Potiorek was planned to be assassinated at the end of March 1914, when the new mufti Čaušević was to be enthroned in Sarajevo. However, upon hearing that Archduke Franz Ferdinand of Austria would come to Sarajevo on Vidovdan, the Black Hand changed their minds. The Archduke's scheduled visit on Vidovdan (28 June), a Serbian national holiday, was perceived as an insult. Ilić summoned Mehmedbašić and informed him on 26 March that the plan now was to murder Archduke Franz