Avvakum

Avvakum Petrov (Russian: Авваку́м Петро́в) (November 20, 1620 or 1621 – April 14, 1682), born in Grigorovo (in present-day Nizhny Novgorod), was a Russian protopope of Kazan Cathedral on Red Square who led the opposition to Patriarch Nikon's reforms of the Russian Orthodox Church. His autobiography and letters to the tsar, Boyarynya Morozova and other Old Believers are considered masterpieces of 17th-century Russian literature.