The growth of the principality of Kiev attracted missionaries from the Byzantine Empire.
One Rus ruler, Vladimir, married the Byzantine emperor’s sister and officially accepted Eastern Orthodox Christianity for himself and his peoples in 988.
Orthodox Christianity became the religion of the state.
Kieven Rus prospered and reached its high point in the first half of the 11th century.
However, civil wars and new invasions brought an end to the first Russian state in 1169.