Olga (Church Slavonic: Ольга;[3][a] Old Norse: Helga;[4] c. 890–925 – 11 July 969)[5] was a regent of Kievan Rus' for her son Sviatoslav from 945 until 957.

[citation needed] According to Alexey Karpov, a specialist in the history of ancient Russia, Olga was no more than 15 years old at the time of her marriage.

After his father's death, Igor was under the guardianship of Oleg, who had consolidated power in the region, conquering neighboring tribes and establishing a capital in Kiev.

The Drevlians had joined Kievan Rus' in military campaigns against the Byzantine Empire and paid tribute to Igor's predecessors.

According to the Byzantine chronicler Leo the Deacon, Igor's death was caused by a gruesome act of torture in which he was "captured by them, tied to tree trunks, and torn in two.

[19] Little is known about Olga's tenure as ruler of Kiev, but the Primary Chronicle does give an account of her accession to the throne and her bloody revenge on the Drevlians for the murder of her husband as well as some insight into her role as civil leader of the Kievan people.

After Igor's death at the hands of the Drevlians, Olga assumed the throne because her three-year-old son Sviatoslav was too young to rule.

The Drevlians, emboldened by their success in ambushing and killing the king, sent a messenger to Olga proposing that she marry his murderer, Prince Mal.

They arrived in her court and told the queen why they were in Kiev: "to report that they had slain her husband ... and that Olga should come and marry their Prince Mal."

The people brought them into the court where they were dropped into a trench that had been dug the day before under Olga's orders where the ambassadors were buried alive.

[21] Olga sent another message to the Drevlians, this time ordering them to "prepare great quantities of mead in the city where you killed my husband, that I may weep over his grave and hold a funeral feast for him.

"[21] According to the Primary Chronicle, five thousand Drevlians were killed on this night, but Olga returned to Kiev to prepare an army to finish off the survivors.

The initial conflict between the armies of the two nations went very well for the forces of Kievan Rus', who won the battle handily and drove the survivors back into their cities.

"[22] As the people fled the burning city, Olga ordered her soldiers to catch them, killing some of them and giving the others as slaves to her followers.

She continued to evade proposals of marriage, defended the city during the Siege of Kiev in 968, and saved the power of the throne for her son.

After her dramatic subjugation of the Drevlians, the Primary Chronicle recounts how Olga "passed through the land of Dereva, accompanied by her son and her retinue, establishing laws and tribute.

Olga's network of pogosti would prove important in the ethnic and cultural unification of the Rus' people, and her border posts began the establishment of national boundaries for the kingdom.

[23] There are three primary sources about this event: a prescriptive account of formalities and etiquette in De Ceremoniis or Book of Ceremonies (c. 950s, written or commissioned by Byzantine emperor Constantine VII Porphyrogennetos in Greek), a brief passage in the Synopsis of Histories (written c. 1070s by Byzantine historian John Skylitzes in Greek), and a long adventurous story in the Primary Chronicle (compiled in Kiev c. 1110s in Old Church Slavonic by an unknown Rus' monk).

[25] John Skylitzes recorded only a very brief passage in chapter 11, section 6 of his Synopsis of Histories: Olga 'came to Constantinople after her husband died.

[d] Francis Butler argues that the story of the proposal was a literary embellishment, describing an event that is highly unlikely to have ever actually occurred.

[33] In 2018, Russian historian and writer Boris Akunin pointed out the importance of a 2-year gap between invitation and arrival of bishops: "The failure of Olga's Byzantine trip has inflicted a severe blow to her party.

Pagan party prevailed, the young Sviatoslav pushed his mother into the background, and that's why the German bishops had to return empty-handed.

"[34] According to Russian historian Vladimir Petrukhin, Olga invited the Roman rite bishops because she wanted to motivate Byzantine priests to catechize the Rus' people more enthusiastically, by introducing competition.

When Sviatoslav announced plans to move his throne to the Danube region, the ailing Olga convinced him to stay with her during her final days.

Only three days later, she died and her family and larger parts of Kievan Rus' mourned:Sviatoslav announced to his mother and his boyars, "I do not care to remain in Kiev, but should prefer to live in Peryaslavets on the Danube, since that is the centre of my realm, where all riches are concentrated; gold, silks, wine, and various fruits from Greece, silver and horses from Hungary and Bohemia, and from Rus' furs, wax, honey, and slaves."

[31] The sarcophagus found in 1826 during excavations of Church of the Tithes conducted by architect Nikolai Efimov was attributed as being Olga's and moved first to the Historical Museum and then to St. Sophia Cathedral.

For she shone like the moon by night, and she was radiant among the infidels like a pearl in the mire, since the people were soiled, and not yet purified of their sin by holy baptism.

[38] A northern Russian manuscript from the 15th century mentions that "when Vladimir unearthed the body of Olga, his grandmother [and discovered that it was] uncorrupted, [he then] placed it in a wooden coffin in the Church of the Tithe".

The Russian Primary Chronicle's claim that Olga was of Viking descent also received attention for its possible contribution to her "warrior spirit".

[54] Russian historian Boris Akunin argues though she certainly reconquered the Drevlians, only her killing of their first envoy is plausible, since Iskorosten was just two days' ride from Kiev, making it difficult to conceal the first public murder.