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 Viktor of Austria-Este had one daughter: Ferdinand, who was a Feldmarschalleutnant (Austrian "two stars" general rank), died at Brno a few months later at the age of 28 from typhus. His widow remarried with Archduke Karl Ferdinand of Austria. Ferdinand is the link in the Jacobite succession between his brother Francis I and his daughter Mary IV and III. Archduke Ferdinand Karl Viktor of Austria-Este Ferdinand Karl Viktor (20 July 1821 – 15 December 1849) was Archduke of Austria-Este and Prince of Modena. Born in Modena, he was the second son of Francis IV of Modena and his niece-consort Maria Beatrice of Savoy.