Vladimir of Kiev
Saint Vladimir (Svyatoslavich), Baptizer of Kyivan Rus' (958-1015) was the Grand Prince of Kiev when Orthodoxy was introduced into present day Russia and Ukraine.
St. Vladimir was a devout pagan in his early life. He was a great conqueror, who had many wives, and erected many pagan statues in the lands that he ruled over.
Upon finding out that other faiths existed beyond his own paganism, he decided to send his envoys out into the world to find out what was true faith on earth.
His envoys met with Muslims, but felt that there was no joy among them, and that their faith was very mechanical. The envoys also met with Jews and Catholics, but were still unimpressed.
Everything, however, changed when St. Vladimir’s envoys arrived in Constantinople. Upon attending Divine Liturgy in the Hagia Sophia, the envoys said “We no longer knew whether we were in heaven or on earth"
Taking the word of his envoys, St. Vladimir had himself and his nation baptized Orthodox.
After St. Vladimir’s Conversion
St. Vladimir changed completely after his baptism. He destroyed all the pagan statues that stood in Kyivan Rus', and replaced them with Churches. He also attempted to live in peace as much as possible with his neighbors, and had only one wife.
St. Vladimir is also the grandson of St. Olga, and the father of Sts. Boris and Gleb the Passion-Bearers.