Battle of Cer On 28 June 1914, Bosnian Serb student Gavrilo Princip assassinated Archduke Franz Ferdinand of Austria in Sarajevo. The assassination precipitated the July Crisis, which led Austria-Hungary to issue an ultimatum to Serbia on 23 July on suspicion that the assassination had been planned in Belgrade. The Austro-Hungarian government made the ultimatum intentionally unacceptable to Serbia, and it was indeed rejected. The Austro-Hungarians declared war on Serbia on 28 July and that same day the Serbs destroyed all bridges on the Sava and Danube rivers in order to prevent the Austro-Hungarians from using them during any future invasion. Belgrade was shelled
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.