The most significant expansion of Orthodox Christianity occurred among the Slavic peoples of what is now Ukraine and western Russia. In this culturally diverse region, which also included Finnic and Baltic peoples as well as Viking traders, a modest state known as Kievan Rus (KEE-yehv-ihn ROOS)—named after the most prominent city, Kiev—emerged in the ninth century. Like many of the new third-wave civilizations, the development of Rus was stimulated by trade, in this case along the Dnieper River, linking Scandinavia and Byzantium. Loosely led by various princes, especially the prince of Kiev, Rus was a society of slaves and freemen, privileged people and commoners, dominant men and subordinate women. This stratification marked it as a third-wave civilization in the making (see Map 10.3).

Religion reflected the region’s cultural diversity, with the gods and practices of many peoples much in evidence. Ancestral spirits, household deities, and various gods related to the forces of nature were in evidence with Perun, the god of thunder, perhaps the most prominent. Small numbers of Christians, Muslims, and Jews were likewise part of the mix. Then, in the late tenth century, a decisive turning point occurred. The growing interaction of Rus with the larger world prompted Prince Vladimir of Kiev to affiliate with one of the major religions of the area. He was searching for a faith that would unify the diverse peoples of his region, while linking Rus into wider networks of communication and exchange. According to ancient chronicles, he actively considered Judaism, Islam, and Roman Catholicism, before finally deciding on Eastern Orthodoxy, the religion of Byzantium. He rejected Islam, the chronicles tell us, because it prohibited alcoholic drink and “drinking is the joy of the Russes.” The splendor of Constantinople’s Orthodox churches apparently captured the imagination of Rus’s envoys, for there, they reported, “We knew not whether we were in heaven or on earth.”14 Political and commercial considerations no doubt also played a role in Vladimir’s decision, and he acquired a sister of the Byzantine emperor as his bride, along with numerous Byzantine priests and advisers. Whatever the precise process, it was a freely made decision. Eastern Orthodox Christianity thus came to Rus without the pressure of foreign military defeat or occupation. Eventually, it took deep root among the Russian people.

It was a fateful choice with long-term implications for Russian history, for it brought this fledgling civilization firmly into the world of Orthodox Christianity, separating it from both the realm of Islam and the Roman Catholic West. Like many new civilizations, Rus borrowed extensively from its older and more sophisticated neighbor. Among these borrowings were Byzantine architectural styles, the Cyrillic alphabet, the extensive use of icons, a monastic tradition stressing prayer and service, and political ideals of imperial control of the Church, all of which became part of a transformed Rus. Orthodoxy also provided a more unified identity for this emerging civilization and religious legitimacy for its rulers. Centuries later, when Byzantium had fallen to the Turks, a few Russian church leaders proclaimed the doctrine of a “third Rome.” The original Rome had abandoned the true faith, and the second Rome, Constantinople, had succumbed to Muslim infidels. Moscow was now the third Rome, the final protector and defender of Orthodox Christianity. Though not widely proclaimed in Russia itself, such a notion reflected the “Russification” of Eastern Orthodoxy and its growing role as an element of Russian national identity. It was also a reminder of the enduring legacy of a thousand years of Byzantine history, long after the empire itself had vanished.