The Russian Orthodox Church to 1453
312-3 the Roman Emperor Constantine is converted and Christianity becomes the official religion of the Roman Empire.
324-30, he builds a new capital of the Eastern Roman Empire called Constantinople and convokes the Council of Nicaea (325) at which the doctrine of the 'one true faith' is worked out.
This is the first of seven councils of bishops of all the Christian churches, where heresies are condemned and church organisation is worked out in detail.
Unresolved at these Councils are differences between the Christian churches of different areas, both on the level of doctrine and liturgy, on the one hand, and on the level of power on the other. The Roman church makes liturgical changes which other churches do not accept. Constantinople gradually becomes the acknowledged leader of the Eastern churches and is seen as a rival to Papal authority.
In 632 the Prophet Mohammed dies and the Islamic religion which he founded spreads rapidly by force of arms: by 680 Arab marauding parties have almost reached Constantinople. The success of Islam in the Near and Middle East leaves the Patriarchate of Constantinople a dominant, but isolated, centre of Christianity in the East.
In the mid-ninth century, Constantinople reaches out to its north with missions to the Balkans and Russia led by the Greek monks Cyril and Methodius. Romania, Serbia and Bulgaria are converted to Eastern Orthodox Christianity using a version of Macedonian known as Old Church Slavonic for the liturgy. The familiarity of the language makes Orthodoxy more easily acceptable to Slavs, a true national religion eventually.
988, St Vladimir converts Russia to Eastern Orthodox Christianity. In Kievan Rus', Christianity favours mercy (St. Vladimir), suffering (Sts. Boris and Gleb) and inner grace rather than outward observance (Metropolitan Ilarion's Sermon on Law and Grace). See also the Testament of Vladimir Monomakh.
1054, the schism between the Catholic and Orthodox churches becomes open with the Pope's excommunication of the Patriarch of Constantinople.
End eleventh century, the writing of Letopisi (chronicles) begins - national and ecclesiastical history from a dynastic standpoint.
End eleventh-mid thirteenth centuries, the Crusades. Catholic Europe invades the Near East. Latin bishops are placed in Jerusalem and Constantinople, driving a further wedge between Orthodox and Catholic.
Thirteenth-fourteenth centuries, with the acceptance of Hesychasm by Orthodox and of Scolasticism by Catholics, the schism widens.
1240-1480, the Mongol Yoke in Russia. The doctrinal chasm is complemented by physical isolation from the West. Russia undergoes neither the Renaissance or the Reformation (in which the Catholic Church splits within itself).
Three saints of the Mongol period.
1438-9, the Council of Florence decrees the need to unify the Catholic and Orthodox churches: this resolution is rejected by the Russian Orthodox church.
1448, the first Russian Metropolitan is elected at Moscow.
1453, Constantinople falls to the Turks: Moscow declares itself the New Rome, the Russian Orthodox church becomes autocephalous ('self-headed').