Russia was Catholic at the time of her conversion (988). The apparent year of 1054 for the Greek schism was only between Constantinople and Rome, and Russia was still considered Catholic (albeit of the Byzantine variety until much later).


On 15 December 1448, Jonah became Metropolitan of Kiev and All Rus' without the agreement of the Ecuмenical Patriarchate of Constantinople, which made the Metropolis of Kiev and all Rus' de facto independent. In response, in 1458 a rival Metropolitan Gregory the Bulgarian was appointed and consecrated by the Pope of Rome as the Byzantine Catholic Metropolitan of Kiev and all Rus'. Metropolitan Gregory was then recognised by Patriarch Dionysius I of Constantinople in 1466; since Constantinople maintained the Union with the Catholic Church until 1484, Kiev returned under Constantinople's jurisdiction. Dionysius therefore demanded in 1467 that all the hierarchs of the Muscovy submit to Gregory, but Moscow peremptorily refused. On the same year, Grand Prince Ivan III of Moscow declared a complete rupture of relations with the Patriarchate of Constantinople.