Olga was the wife of Prince Igor of Kiev. After he was killed by the Drevlians in 945 for raising tribute beyond agreement, she ruled as regent for her young son Svyatoslav and avenged her husband through a famous series of stratagems against the Drevlian envoys — buried alive, scalded, and finally massacred when she set fire to their pigeons.
After this terrifying display of pagan princess-vengeance — recorded in detail by the Russian Primary Chronicle — she traveled to Constantinople around 957, was baptized by the patriarch with the new name Helena (after Constantine's mother), and was received personally by Emperor Constantine VII Porphyrogenitus who served as her godfather.
On her return to Kiev she labored unsuccessfully to convert her son Svyatoslav, who remained pagan throughout his life. Olga's grandson Vladimir, however — born about ten years before her death — was profoundly influenced by her memory, and in 988 baptized the entire Rus' people, founding the Russian Orthodox Church directly on the religious foundations Olga had laid.
She is honored as Equal-to-the-Apostles by the Eastern Orthodox Churches and as a saint by the Catholic Church. Her tomb at the Pechersk Lavra in Kiev was for centuries the principal foundation of Russian-Ukrainian Christian devotion.