Produced in France, "Magnificent Sinner" stars Curd Jürgens as Tsar Alexander II, with Romy Schneider as the schoolgirl Katia who first becomes his mistress, before being elevated to the rank of princess. The romance between emperor and commoner leads to court intrigue and a weakening of the ties of loyalty between the Tsar's ministers and their ruler, and is instrumental in Alexander's ultimate assassination.