His Glorious Night (1929)

Being engaged against her will with a wealthy man, Princess Orsolini (Catherine Dale Owen) is in love with Captain Kovacs (John Gilbert), a cavalry officer she is secretly meeting. Her mother Eugenie (Nance O'Neil), who has found out about the affair forces her to dump Kovacs and take part in the arranged marriage. Though not believing her own words, Orsolini reluctantly tells Kovacs she cannot ever fall in love with a man with his social position. Feeling deeply hurt, Kovacs decides to take revenge by indulging in blackmail, spreading a rumor that he is an imposter and a swindler.