Olga (Saint Olga, Helga)(c.880-969), belonged to the Scandinavian aristocracy in Russia (Rus', Varangians) and married the future Igor, prince of Kiev in 903. After his death, she ruled Kievan Rus as regent (945-c.963) for their son, Sviatoslav I. She spent great effort to avenge her husband's death at the hands of the Derevlians, and succeeded in slaughtering most of them. She was the first Rus ruler to convert to Christianity, sometime between 954 and 958. However, she failed to convert Sviatoslav, and it was left to his son and successor Vladimir I to make Christianity the lasting state religion.

Preceded by:
Igor
Rulers of Kievan Rus Succeeded by:
Sviatoslav I