One of the most interesting tales to come out of the Slavic states was that of Princess Olga of Kiev, and her bloody campaign of revenge.
In the early part of the 10th Century, Prince Igor of Kiev, who was on the throne of the Kievan Rus (the Rurik Dynasty of the Russian Tsars), traveled to meet the Slavic tribe, the Drevlyans, a tribe that owed him tribute. When Igor demanded more than the Drevlyans thought his rule was worth, instead of paying him, they simply killed him. Igor's wife Olga subsequently took rule of the Rus as her son was too young to rule, although Olga did not take kindly to Igor's death at all, hell hath no fury.
The Drevlyans weren’t so keen on having a female leader, so they decided to send their twenty best men to negotiate a marriage between Olga and Prince Mal (their top choice for king). Olga's response to this proposition was to order her Army to dig a large trench and then drop the twenty ambassadors into the trench and bury them all alive.
Following this Olga sent word to Prince Mal that she had accepted his proposal, but required the Drevlyans to send their most distinguished suitors to accompany her on the voyage. Once the Drevlyans arrived, she invited them all into the Bath House to clean up. She then proceeded to lock the doors, and set fire to the Bath House, burning all of the Drevlyans alive. Soon after this Olga held a funeral feast in Igor's honour where she invited the Drevlyans to attend. It was a merry affair, until the Drevlyans got drunk, and Olga's army then proceeded to kill 5,000 of their men. Olga then prepared her Army to attack what survivors of the Drevlyans that remained.
The remaining Drevlyan survivors pleaded for mercy to Olga, to spare what was left of the Drevlyans. Olga granted the survivors mercy on the condition that each house send her three pigeons and three sparrows. Once the pigeons and sparrows arrived in Kiev, Olga ordered her Army to tie sulfur bound in cloth to each pigeon, and then one night they sent all of the pigeons and sparrows back to the Drevlyans so they would all arrive at once. Once all of the pigeons and sparrows returned to their nests, each house of the Drevlyans was set ablaze.
What Drevlyans remained fled the city, however Olga ordered her Army to recapture them all, some of which she executed, and rest she sold into slavery. In her final act of revenge, she ordered her Army to burn what was left of the Drevlyan city to the ground.
Uncannily enough, despite Olga's bloody campaign of revenge, she was later ordained as a Saint in Roman Catholicism and Russian Orthodoxy.