The effects of censorship and political power on opera librettos was a topical issue in nineteenth century Russia and during the first half of the twentieth century in the Soviet Union. It reflected the conflicts between art and these totalitarian regimes, first under the Czar, and thereafter with the Soviets. During the reign of Czar Nicholas I, operas in French were regarded as dangerous, and were mostly modified by translators-adapters. For instance, The Mute Girl of Portici, William Tell, or Robert the Devil, were transformed in order to get rid of everything that could recall the people's struggle for liberty and independence. National operas were however censored as well, such as the first version of Boris Godunov. During the postrevolutionary and Soviet eras, the regime went on resorting to censorship, particularly of national operas like for instance Life for the Czar and Lady Macbeth of Mtsensk Distric. With Perestroika, operas reappeared in their original version and in the original language, the country's ideology which was undergoing a profound change could no longer be endangered. Eventually, in January 2000, the Mariinski Theatre of Saint Petersburg used Russian subtitles for Mozart's Don Giovanni, for the first time.