Directed by Serge de Poligny Written by Louis Chavance Jean Cocteau Serge de Poligny André Lefaur as Eustache Dauphin dit Monseigneur - le faux Louis XVII Odette Joyeux as Elfy de Saint-Hélié Jany Holt as Anne Alain Cuny as Hervé Gabrielle Dorziat as La comtesse de Saint-Helie André Alerme as Le colonel Aimé Clariond as L'évêque Marguerite Pierry as Fébronie Dauphin Claude Sainval as Albéric de Marignac Charles Vissière as Toussaint - le domestique Jean Cocteau as Le baron Julius Carol - le baron fantôme Marguerite de Morlaye as Une vieille dame Marcel Pérès (actor) as Léopold - le frère de Fébronie Jean Diéner - Joseph as le cocher Jacques Ory as Hervé enfant Marie Magali as Elfy de Saint-Hélié enfant Mercédès Brare as Anne enfant