Vittorio De Sica was a huge fan of 'Max Ophuls' and wanted Jean Gabin's role in Le Plaisir (1952). Ophuls told him no, but that he would find him a dignifying role in another film. The Role of the Baron was written with him in mind for this film.
'Charles Boyer' often fought with 'Max Ophuls' about his character's motives. Ophuls one day during rehearsal broke down and said "Enough! His motives are he is written that way!" Boyer never asked him again and decided to play his character as being omnipotent in all his scenes.
Was originally released with a longer ending where you see the earrings being passed from a young Nun to a young woman marrying a General. This was meant to create a circular structure for the film with the young woman representing the next Madam DE. However 'Max Ophuls' felt it weakened the film when it was finished and personally cut it from the final prints.