Passage: Kievan Rus' is important for its introduction of a Slavic variant of the Eastern Orthodox religion, dramatically deepening a synthesis of Byzantine and Slavic cultures that defined Russian culture for the next thousand years. The region adopted Christianity in 988 by the official act of public baptism of Kiev inhabitants by Prince Vladimir I, who followed the private conversion of his grandmother. Some years later the first code of laws, Russkaya Pravda, was introduced by Yaroslav the Wise. From the onset the Kievan princes followed the Byzantine example and kept the Church dependent on them, even for its revenues, so that the Russian Church and state were always closely linked.

Question: Why is Kievan Rus so important?
introduction of a Slavic variant of the Eastern Orthodox religion