AVVAKUM (1620/1–1682), Russian Orthodox arch-priest; founding father of the Old Believers; martyr. Avvakum was ordained to the priesthood at the age of twenty-two, serving in the area of Nizhni Novgorod; eight years later he was promoted to be archpriest. By then he had amply demonstrated his zeal as a reformer. Following in the wake of the Muscovite "God-seekers," an influential group of scholarly zealots, he sought to revive liturgical life and public morality. The resentment which this provoked led to his displacement and his first visit to Moscow (1652). There he was welcomed by the leading God-seekers and introduced to the tsar.

The election of Nikon as patriarch of Moscow later that year promised to confirm and revitalize the God-seekers' reforms. However, Nikon proceeded arbitrarily to reform liturgical phraseology and practice, particularly concerning the sign of the cross. Avvakum vociferously objected to these reforms, which he saw as a challenge...