The story of Prince Stepán Kasátsky discovering his fiancée was the mistress of the Czar, so he then becomes a monk.

Ivan Mosjoukineas Prince Kasatsky, later Father Sergius
Olga Kondorovaas Countess Korotkova
Vladimir Gajdarovas Tsar Nikolai I
Nikolai Panovas Kasatsky's father
Nathalie Lissenkoas Widow of the merchant Makovkin
Iona Talanovas Merchant
Vera Orlovaas Merchant's daughter
Pyotr Baksheyevas Young priest
Polikarp Pavlovas Monastery's gatekeeper