The 1939 version of The Man in the Iron Mask. Directed by James Whale and starring Louis Hayward (in the dual roles), Joan Bennett, Joseph Shildkraut and Alan Hale. This was a favorite of my father and was released on a DVD by Hen’s Tooth.
Not a bad sequel to Peyton Place except for the fact that all the major rolls are re-cast with different actors. In the early 60s 20th-Fox released this and the original as a double bill when they saw that The Robe/Demetrius & the Gladiators did well as a pair. Mary Astor steals every scene...