(An old mistress) is an 1851 novel by the French writer Jules Barbey d'Aurevilly. It tells the story of a wayward dandy who falls in love with a young woman but is unable to fully leave his former mistress behind. The book was published by Alexandre Cadot in three volumes, with 327, 316 and 341 pages respectively.[1] It was the basis for the 2007 film The Last Mistress directed by Catherine Breillat.[2]