NIKON (1605–1681), patriarch of Moscow, Russian Orthodox church reformer. Nikon briefly dominated the Russian political and ecclesiastical scene in the mid-seventeenth century. Not least of his achievements was that he rose from utter obscurity to do so. He served a Moscow parish for ten years but turned his back on the capital in the early 1630s when his three children all died suddenly. Both he and his wife decided to become monastics. Much of the time Nikon lived as a solitary (1634–1643). He was, however, elected abbot of the Kozheezero hermitage and by 1646 was abbot of an important monastery in Moscow. There he was befriended by the tsar. Hardly three years later he was appointed metropolitan (archbishop) of Novgorod and by 1652 was in line for election to the patriarchal throne itself.

By this time Nikon was clearly aligned with the reformers of the Russian church, the "God-seekers." They had encouraged...