Great Prince of Kiev Vladimir, July 28/15

The holy and right-believing Vladimir (Svyatoslavich), Baptizer of Kievan Rus' (958-1015) was the Grand Prince of Kiev when Orthodoxy was introduced into present day Russia and Ukraine. He is also the grandson of St. Olga, and the father of Sts. Boris and Gleb the Passion-Bearers (and the first saints of the Russian lands). He is commemorated by the Church on July 28/15
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.
St. Vladimir changed completely after his baptism. He destroyed all the pagan statues that stood in Kievan 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.
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 changed, however, when the envoys arrived in Constantinople. Upon attending Divine Liturgy in 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 into the Orthodox Church.