Olga’s origins are unknown. Although she may have come from Pskov, according to the Russian Primary Chronicles, she came from Vyshgorod. She was probably of Varangian heritage. She is believed to have been born about 890. About 903 she married Prince Igor I, who was the son of the founder of Russia, Rurik. Prince Igor succeeded his father Oleg as the ruler of Kiev and its territories, which now constitute parts of a number of present day nations: Russia, Ukraine, Belarus, and Poland.
In 945, Olga was Queen in Russia. Her husband, King Igor, had been killed by Derevlyanins. Her son was only three years old. She reigned until her son was of age. Ensuring there would be no threats to either of them, she went after the barbarians. She used clever ways to keep them from ever thinking of attacking her or her son. The first group she had buried alive, the next ones boiled in baths. Then her army went after any stragglers.
She was known as a strong and effective ruler. In 955 she introduced the Greek Orthodox form of Christianity to all of Russia. Her feast day is July 11.
She visited Emperor Constantine VII in Constantinople. He admired her looks and intelligence. Before her baptism, Constantine asked her hand in marriage, but Olga deferred claiming that she wanted to be baptised an Orthodox Christian first. Again, after the baptism, Constantine requested her hand in marriage, but the quick-thinking Olga tricked him (since he was her godfather in baptism), noting that he called her his daughter in baptism and so such a union is forbidden under Christian law. While Constantine commented to Olga about her trickery, he lavished gifts on her when she returned to Kiev. In Kiev she instructed her son, Svyatoslav, and entreated him to be baptized. While he could not bring himself to commit to baptism, he would not forbid others.
Uppity Women of Medieval Times by Vicki Leon