The beginnings of Russian Christianity may possibly be found, as the patriarch Photius asserted, before the results of the defeat of the barbarians by John Zimisces. But it was not till nearly a century later that anything notable occurred. Olga, a "ruler of Russia," visited Constantinople in 957 and was baptized. Yet the Greek missionaries made but slow progress. It was not till Vladimir married the sister of the emperor Basil in 989, and restored the city of Cherson,--in which Cyril more than a century before had been a missionary,--where he was baptized, to the Empire, that the evangelisation of Russia really began. Vladimir deliberately chose the Greek in preference to the Roman form of Christianity, and acted, it would seem, with some semblance of national consent. The baptism of the people of {127} Kiev in the waters of the Dnyepr, as one flock, "some standing in the water up to their necks, others up to their breasts, holding their young children in their arms," was typical of the national acceptance of Christ. Everywhere churches and schools were built and the Slavonic Scriptures taught the people; at Kiev was built the Church of S. Sophia by Greek masons, in commemoration of the debt to the great Church of the New Rome. [Sidenote: S. Vladimir, 989.] Vladimir became the apostle of his people. The Church pressed forward eagerly, forward over the vast expanse covered by the Russian power, and, not without martyrdoms and tales of heroic adventure, won its way triumphantly to Russian hearts. [Sidenote: The conversion of the Czechs.]