Oleg the Wise was a prominent ruler of the East Slavs during the late 9th and early 10th centuries. He is best known for founding the state of Kievan Rus, which became a significant political and cultural center in Eastern Europe. Oleg expanded his territory through military conquests and strategic alliances, notably capturing the city of Kyiv. Oleg is also remembered for his diplomatic skills, particularly in establishing trade relations with the Byzantine Empire. His reign is often seen as a period of consolidation and growth for the early Slavic states, laying the groundwork for future leaders and the development of Russian identity.