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
Black Hand (Serbia) Balkan Wars. By this point, disagreeing with the Black Hand was dangerous, as political murder was one of their tools. It was also in 1914 that Apis allegedly decided that Archduke Franz Ferdinand, the heir-apparent of Austria, should be assassinated, as he was trying to pacify the Serbians, and if this happened then a revolution would never occur. Towards that end it is claimed that three young Bosnian Serbs were recruited to kill the Archduke. They were definitely trained in bomb throwing and marksmanship by current and former members of the Serbian military. Gavrilo Princip, Nedeljko Čabrinović and Trifko Grabež