St Cyprian was a Serbian [[clergy]]man of Bulgarian nationality who struggled on [[Mount Athos]]. In 1373, the [[Patriarch]] of [[Constantinople]] [[Philotheus I (Kokkinos) of Constantinople|Philotheus Kokkinos]] picked him for his devout lifestyle and excellent education and sent him to Lithuania and Russia. His mission there was to reconcile the princes of Lithuania and Tver with [[Alexis of Moscow|Metropolitan Alexis]]. In 1375, after the hostilities between Moscow and Lithuania had started all over again, the Lithuanian princes asked to appoint Cyprian their [[metropolitan]]. Patriarch Philotheus Kokkinos made Cyprian the Metropolitan of Kiev,
all Rus and Lithuania, so that he could unite both ecclesiastical provinces after the [[death]] of Metropolitan Alexis.
In 1378, Metropolitan Alexis died. As a result of the ensuing skirmishes and intrigues, Cyprian became Metropolitan of Moscow in 1381. One year later, however, he fled from Moscow due to the approaching armies of Tokhtamysh. Subsequently, he was removed from the Muscovy and replaced by Metropolitan Pimen (1382-1384). The latter was succeeded by Metropolitan Dionysius (1384-1385). In 1390, Cyprian was returned to Moscow by Vasili II,
who he had always supported, and appointed Metropolitan of Moscow and all Russia.
Cyprian is remembered as a wise and experienced keeper of the Church of God and a zealot of the unity of the Russian lands. In fact, he is mainly responsible for uniting the Church in all of the lands, even including those of the Grand Duchy of Lithuania. He was an erudite person and a connoisseur of ecclesiastical rituals and literature who especially cared for regulating the [[Divine Liturgy|divine service]] and [[monasticism|monastic]] lifestyle. St Cyprian was the one who initiated the creation of the ''Троицкая летопись'' (Troitskaya letopis’, or ''Troitskaya Chronicle'') and, probably, the ''Правосудие митрополичье'' (Pravosudiye metropolich’ye, or ''Metropolitan Justice''). He also rewrote the ''Life of Metropolitan Peter'', which had been written around 1327, and made it more rhetorical and well-phrased. Cyprian corrected mistakes in [[Bible|biblical]] books and translated ecclesiastical works from Greek. This was a trying effort, considering the fact that printing had not been invented yet.