Patriarch Nikon was a prominent figure in the Russian Orthodox Church during the 17th century. Born in 1605, he became the Patriarch of Moscow in 1652 and is best known for his efforts to reform church practices and align them more closely with those of the Greek Orthodox Church. His reforms included changes in liturgical practices and the introduction of new church books. Nikon's reforms faced significant opposition, leading to a schism within the church. The dissenters, known as the Old Believers, rejected his changes and maintained traditional practices. Nikon's tenure ended in 1666 when he was deposed, but his influence on the Russian Orthodox Church remains significant.