Старообрядчество
Since none of the bishops joined the Old Believers movement after the schism of 1666-67 in the Russian Orthodox Church, except bishop Paul of Kolomna, who was executed, ordained priests of the old rite would have soon become extinct. Two responses appeared to this dilemma: the “priestist” Old Believers (поповцы (Popovtsy)) and the non-priestist Old Believers (беспоповцы (Bespopovtsy)).