In 1721, the Russian Tsar Peter the Great prohibited the publication of books in Ukraine, except for Russian-language religious works, and decreed that Ukrainian books and records were to be burned. In 1786, it was decreed that services in the Ukrainian Orthodox Church were to be conducted using only the Russian pronunciation of Old Church Slavonic, and not the Ukrainian pronunciation. Decrees in 1863, 1876, and 1881 prohibited the publication and importation of Ukrainian books, as well as the public use of the Ukrainian language in general. The Russian regime of the day viewed the use of Ukrainian as evidence of political opposition and harshly suppressed it.