Fortress of Arad their honor. The most famous prisoner in the fortress of Arad was undoubtedly Gavrilo Princip, who on 28 June 1914 killed the heir to the throne of Austria-Hungary, Archduke Franz Ferdinand and his wife, Sophie, in Sarajevo, which led to the outbreak of World War I. About the inhuman conditions in which prisoners were held in the fortress of Arad warned Ştefan Cicio Pop, deputy of the Romanian National Party in an interpellation to the Hungarian parliament in Budapest during 1917. After the first World War, the fortress was occupied by allied Serbian and French troops under French command, until
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.