Prophetic Oleg was the first prince of Kievan Rus, primarily described in chronicles. His name is mentioned in the well-known "Tale of Bygone Years" as well as in lesser-known local sources. According to some of them, Oleg was a relative of Rurik, the brother of his wife Efanda. After Rurik's death, Oleg became regent for his underage son Igor.

Prince Oleg significantly contributed to the wealth of Rus and strengthened its reputation in relations with neighboring states. In 882, he liberated Smolensk and Lyubech, and by killing Askold and Dir, he captured Kyiv. Oleg liked the city and made it the capital of the Ancient Russian state. The new authority in the person of Prophetic Oleg was quickly recognized by the Slavic tribes: Polans, Severians, Drevlians, Ilmen Slavs, Krivichs, Vyatichs, Radimichs, Ulichs, Tiverians, and others. Additionally, he organized state governance so that local princes and governors would assist him. Subsequently, Oleg continued the expansion of the state, annexing nearby territories. Under his rule, in 883, the lands of the Drevlians came under control, in 884, the Severians, and in 885, the Radimichs. The legendary campaign of Oleg against Byzantium holds an important place in historical documents: in 907, he gathered a large army and moved towards Tsargrad, which soon surrendered, agreeing to pay tribute to the Russian principalities. Oleg's foreign policy also included a long struggle against the Khazars, who forcibly collected tribute from Russian lands.

Historians believe that the nickname "Prophetic" has two meanings. The first, in the Old Russian language, meant wisdom and calculation. The second, more controversial, implies old-fashionedness, as most of the population of Rus at that time adhered to paganism and polytheism, which showed their superstition and shortsightedness compared to developed states.

Prince Oleg died in 912.