(Mikhail Klimentyev, Sputnik, Kremlin Pool Photo via AP, File) In this Saturday, July 28, 2018, file photo, Russian Orthodox Church Patriarch Kirill, left, leads a religious service as Russian President Vladimir Putin, right, and Eastern Orthodox Patriarch of Alexandria and all Africa Theodoros II, second right, attend a ceremony marking the 1,030th anniversary of the adoption of Christianity by Prince Vladimir, the leader of Kievan Rus. The loose federation of Slavic tribes preceded the Russian state.