Great Moscow Synod in the context of "Old Believers"

Nikon (Russian: Ни́кон, Old spelling: Нїконъ), born Nikita Minin (Никита Минин; 7 May [O.S. 27 April] 1605 – 17 August [O.S. 7 August] 1681) was the seventh Patriarch of Moscow and all Rus' of the Russian Orthodox Church, serving officially from 1652 to 1666. He was renowned for his eloquence, energy, piety and close ties to Tsar Alexis of Russia. Nikon introduced many reforms, including liturgical reforms that were unpopular among conservatives. These divisions eventually led to a lasting schism known as Raskol (schism) in the Russian Orthodox Church. For many years, he was a dominant political figure, often equaling or even overshadowing the Tsar. In December 1667, Nikon was tried by a synod of church officials, deprived of all his sacerdotal functions, and reduced to the status of a simple monk.

The Schism of the Russian Church, also known as raskol (Russian: раскол, pronounced [rɐˈskoɫ], meaning 'schism'), was an era of religious and social turmoil in Russia spanning from the late 1660s to the early 1690s, during which dissenters opposing the hierarchy of the Russian Orthodox Church appeared in great numbers, and were persecuted and suppressed by ecclesiastical and secular authorities.

The schism followed the liturgical and ritual reforms enacted by Patriarch Nikon at the behest of Tsar Alexis from 1652 to 1657, which aimed to remove all difference between the Russian rite and that of the Greek Orthodox Church, from which Christianity was imported to the nation. Both Tsar and Patriarch were convinced that local practices diverged from the Greek ones due to faulty transmission and scribal errors throughout centuries of Russian parochialism. Nikon's reforms engendered opposition from within the church in defense of traditional custom, voiced first by relatively minor figures such as priest Ivan Neronov, but later augmented by leading clergymen headed by Bishop Alexander of Vyatka and Archimandrite Spiridon Potemkin. Tsar Alexis attempted to reconcile the controversy by convening the 1666-1667 Great Moscow Synod, where the old rite was anathemized and declared heretical, and the reformed rite was proclaimed universally binding.

The Schism of the Russian Church, also known as raskol (Russian: раскол, pronounced [rɐˈskoɫ], meaning 'schism'), was an era of religious and social turmoil in Russia spanning from the late 1660s to the early 1690s, during which dissenters opposing the authority of the Russian Orthodox Church appeared in great numbers, and were persecuted and suppressed by the ecclesiastical hierarchy and secular government.

The schism followed the liturgical and ritual reforms enacted by Patriarch Nikon at the behest of Tsar Alexis from 1652 to 1657, which aimed to remove all difference between the Russian rite and that of the Greek Orthodox Church, from which Christianity was imported to the nation. Both Tsar and Patriarch were convinced that local practices diverged from the Greek ones due to faulty transmission and scribal errors throughout centuries of Russian parochialism. Nikon's reforms engendered opposition from within the church in defense of traditional custom, voiced first by relatively minor figures such as priest Ivan Neronov, but later augmented by leading clergymen headed by Bishop Alexander of Vyatka and Archimandrite Spiridon Potemkin. Tsar Alexis attempted to reconcile the controversy by convening the 1666-1667 Great Moscow Synod, where the old rite was anathemized and declared heretical, and the reformed rite was proclaimed universally binding.