Count Jean Marie Henri Marc Arnoult de Castellane (24 April 1868 – 13 September 1965) was a French politician and member of the house of Castellane.

[1] Among his three siblings were Boniface (who married American railroad heiress Anna Gould, the daughter of Jay Gould),[2][3] and Stanislas de Castellane ( who married Natalia Terry y Sanchez, sister of architect Emilio Terry).

[5] His aunt, Marie de Castellane, was married to Prince Antoine Radziwiłł, a grandson of Prince Antoni Radziwiłł and Princess Louise of Prussia.

[6] He initially served as a cavalry officer but left the army in 1902 to stand in the legislative elections in Cantal.

The widow of Charles Egon IV, Prince of Fürstenberg, she was the youngest daughter of Louis de Talleyrand-Périgord, Duke of Valençay, of Talleyrand, and of Dino,[9] and the Countess Hatzfeldt (widow of Maximilian von Hatzfeldt, née Rachel Elisabeth Pauline de Castellane).