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
Archduchess Elisabeth Amalie of Austria Saxony, he had no children. With his second wife Princess Maria Annunciata of Bourbon-Two Sicilies, Karl Ludwig fathered Archduke Franz Ferdinand of Austria, who became heir to the throne of Austria-Hungary, as well as three other siblings. Elisabeth and her older sister Archduchess Maria Annunziata of Austria (later Abbess of the Theresia Convent in the Hradschin, Prague) were the product of his third marriage to Infanta Maria Theresa of Portugal, a daughter of the deposed King Miguel I of Portugal. In addition, her father was a younger brother of Franz Joseph I of Austria, the reigning emperor at the time