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
Assassination of Archduke Franz Ferdinand wife planned to visit Sarajevo to open the state museum in its new premises there. Duchess Sophie, according to their eldest son, Duke Maximilian, accompanied her husband out of fear for his safety. As Sophie, although of high aristocratic birth, was not from a dynastic family, her union with the Habsburg heir presumptive could only be a morganatic marriage. Emperor Franz Joseph had only consented to their marriage on the condition that their descendants would never ascend the throne. The 14th anniversary of their marriage fell on 28 June. As historian A. J. P. Taylor observes: Franz Ferdinand was an