Sophie, Duchess of Hohenberg
Franz Ferdinand, Duke of Hohenberg (13 September 1927 – 16 August 1977), was the eldest son of Maximilian, Duke of Hohenberg and Countess Maria of Waldburg zu Wolfegg und Waldsee. He was also a grandson of Archduke Franz Ferdinand of Austria and his morganatic wife Sophie, Duchess of Hohenberg. As a result of that morganatic marriage, the Hohenbergs were excluded from the line of succession to the Austro-Hungarian throne.