Mayerling (1936)
Mayerling is a 1936 French historical drama film directed by Anatole Litvak and produced by Seymour Nebenzal from a screenplay by Marcel Achard, Joseph Kessel and Irma von Cube, based on the 1930 novel Idyll's End by Claude Anet. The film stars Charles Boyer and Danielle Darrieux with René Bergeron, Jean Davy, Jean Dax, Jean Debucourt and Gabrielle Dorziat, and Jean-Louis Barrault in a bit part. It is based on the real life story of Crown Prince Rudolf of Austria, his affair with the 17-year old Baroness Maria Vetsera and their tragic end at Mayerling.
More at Wikipedia.