Causes of World War I corrective." British Diplomat Arthur Nicolson wrote in May 1914, “Since I have been at the Foreign Office I have not seen such calm waters.” On 28 June 1914, Archduke Franz Ferdinand of Austria, heir presumptive to the Austro-Hungarian throne, and his wife, Sophie, Duchess of Hohenberg, were shot dead, by two gun shots in Sarajevo by Gavrilo Princip, one of a group of six assassins (five Serbs and one Bosniak) coordinated by Danilo Ilić, a Bosnian Serb and a member of the Black Hand secret society. The assassination is significant because it was perceived by Austria-Hungary as an existential challenge
Archduke Ferdinand Karl of Austria the emperor's knowledge or consent, having eloped two years before the marriage was revealed publicly. On 6 August 1911 he renounced his rights and titles as a dynast of the House of Habsburg and assumed the name of "Ferdinand Burg", at the demand of Emperor Franz Joseph. Henceforth he absented himself from the Viennese court and lived in Tyrol. By then Ferdinand Karl was suffering from tuberculosis, of which he died in 1915. He and his wife had no children. Archduke Ferdinand Karl of Austria Archduke Ferdinand Karl of Austria, later known as Ferdinand Burg (Ferdinand Carl Ludwig Joseph Johann