St. Basil the Blessed
Cathedral of St. Basil the Blessed in Moscow.
Russian Orthodox Church
Russian Orthodox Church, one of the largest autocephalous, or ecclesiastically independent, Eastern Orthodox churches in the world. Its membership is estimated at more than 90 million. For more on Orthodox beliefs and practices, see Eastern Orthodoxy. Christianity was apparently introduced into the East Slavic state of Kievan Rus by Greek missionaries from Byzantium in the 9th century. An organized Christian community is known to have existed at Kiev as early as the first half of...