Raskol, division in the Russian Orthodox Church in the 17th century over reforms in liturgy and forms of worship. Over the centuries, many features of Russian religious practice had been inadvertently altered by unlettered priests and laity, removing Russian Orthodoxy ever further from its Greek Orthodox parent faith. Reforms intended to remove these idiosyncrasies were instituted under the direction of the autocratic Russian patriarch Nikon between 1652 and 1667. The large group of traditionalists who resisted these changes, denouncing them as the work of the Antichrist, came to be known as Raskolniki (“Schismatics”), or Old Believers. See Old Believer.