c. 950–11th century

The Baptism of Rus

Around 950 Princess Olga was baptized by German missionaries. But Christianity's greatest advance in Rus came under her grandson Vladimir (988–990). He married Anna, sister of Byzantine emperor Basil II, and converted to Christianity. He devoted the rest of his life to evangelizing the country. Eastern Orthodoxy became the dominant religion.

His son Yaroslav strengthened ties with Constantinople, moving further away from Rome.

The outstanding theologian of this "Kievan period" was Ilarion, the first Russian bishop of Kiev. He interpreted the Bible allegorically and wove the baptism of Rus into salvation history. Under the influence of Cyril and Methodius's legacy, he laid the foundations of a Russian Christian philosophy of history.