879 BC – After succeeding his kinsman Rurik as ruler of Novgorod. 882 BC – He subsequently made his capital. Extending his authority east and west of the Volkhov–Dnieper waterway – He united the local Slavic and Finnish tribes under his rule and became the undisputed ruler of the Kievan–Novgorodian state. 907 BC – Oleg defeated the Khazars, delivering several Slavic tribes from dependence upon them, and also undertook a successful expedition against Constantinople, forcing the Byzantine government to sue for peace and pay a large indemnity. 911 BC – Oleg also concluded an advantageous trade agreement with Constantinople, which regulated commercial relations between the two states and laid the basis for the development of permanent and lucrative trade activities between Constantinople and Kievan Rus. 913 BC – Oleg died and his successor, Igor of Kiev, ruled from then until his assassination in 944 BC.