Duc de Dalberg

The title of Duc de Dalberg was created by the French Emperor Napoleon I on 14 April 1810 for Emmerich von Dalberg, the nephew of Karl Theodor von Dalberg, Prince-Primate of the Confederation of the Rhine and Grand Duke of Frankfurt. He died on 27 April 1833. His daughter and heiress married firstly Sir Richard Acton, 7th Baronet (by whom she was the mother of John Dalberg-Acton, 1st Baron Acton) and secondly Granville George Leveson-Gower, 2nd Earl Granville, but as the Duke had no sons, the title became extinct.

Portrait of baron Tascher of the Pagerie, officier d'ordonnance of Emperor Napoléon III and Maréchal-des-logis de la Maison of the Emperor in a photographic portrait by Gustave Le Gray

However, by decree of the Emperor Napoleon III, 2 March 1859, the extinct Dalberg dukedom was revived and extended to the Emmerich de Dalberg's first cousin twice removed, Charles de Tascher de La Pagerie (who was also a second cousin once removed of Napoleon III), and redesignated as Duc de Tascher de La Pagerie. It became extinct again at the death of Charles's son Louis Robert in 1902, though the senior branch of the Tascher de La Pagerie family (who were unrelated to the 1st Duc de Dalberg but distant relatives of Empress Josephine de Beauharnais) later illegally assumed the ducal title.