Excerpts from Books and Wikipedia
"As Pierre Pascal observed, ‘after Nikon, Russia no longer had a church: it had a religion of state’. It was left to the even more imperious Peter the Great to reduce the Church to being a department of state. When Patriarch Adrian died in 1700, the office was simply left vacant. The coup de grâce was delivered in 1721 when the patriarchal office was formally abolished and its functions transferred to a government-appointed synod." [Blanning: Pursuit of Glory, p. 376] "Nikon (...), born Nikita Minin (...) 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 which eventually led to a lasting schism known as Raskol in the Russian Orthodox Church. For many years he was a dominant political figure, often equaling or even overshadowing the Tsar. His liturgical reforms were unpopular among conservatives. In December 1666, Nikon was tried by a synod of church officials, deprived of all his sacerdotal functions, and reduced to the status of a simple monk." [Wikipedia]