Olga of Kiev

Olga assumed power in 945 after the Drevlians killed her husband Igor, and her response was systematic: she subjugated the tribe that had taken him. For twelve years she ruled as regent for her son Sviatoslav, holding the throne until 957. Somewhere in that span she accepted baptism and took the name Elena, making her the first Kievan ruler to convert — though it would be her grandson Vladimir, not her son, who eventually imposed Christianity as the state religion. She died on 11 July 969. The Eastern Orthodox Church canonized her with the rare title "Equal to the Apostles," and her feast day…