The Vikings did not only sail west; they also traveled east along the great rivers of Europe. These Swedish Vikings, known as 'Varangians' or 'Rus',' established trade routes connecting the Baltic Sea to the Byzantine Empire and the Caliphate. In 882, the Varangian prince Oleg captured Kiev, uniting it with Novgorod to form the Kievan Rus'. This state became a powerful medieval power and is considered the cultural and political ancestor of modern Russia, Ukraine, and Belarus. The Rus' adopted Orthodox Christianity from the Byzantines in 988, a decision that would define the religious and cultural trajectory of Eastern Europe for over a millennium.