Sharon Tate's voice is dubbed.
Sidney J. Furie and Michael Anderson (I) were originally approached to direct the film.
Originally Kim Novak was cast in the role of Catherine de Montfaucon. Filming began in the fall of 1965 in France. Near every scene had been filmed when Kim Novak fell from a horse and wasn't able to complete her scenes. Deborah Kerr was hired to take over and every scene that featured Miss Novak had to be re-shot with her replacement.
This was the official film debut of Sharon Tate; in the opening credits, it says"and introducing Sharon Tate"