In 988, having taken the town of Chersonesos in Crimea, he boldly negotiated for the hand of emperor Basil II's sister, Anna.[20] Never before had a Byzantine imperial princess, and one "born in the purple" at that, married a barbarian, as matrimonial offers of French kings and German emperors had been peremptorily rejected. In short, to marry the 27-year-old princess to a pagan Slav seemed impossible. Vladimir was baptized at Chersonesos, however, taking the Christian name of Basil out of compliment to his imperial brother-in-law; the sacrament was followed by his wedding to Anna. Returning to Kiev in triumph, he destroyed pagan monuments and established many churches, starting with a church dedicated to St. Basil,[21] and the Church of the Tithes (989).
Arab sources, both Muslim and Christian, present a different story of Vladimir's conversion. Yahya of Antioch, al-Rudhrawari, al-Makin, Al-Dimashqi, and ibn al-Athir all give essentially the same account.[22] In 987, Bardas Sclerus and Bardas Phocas revolted against the Byzantine emperor Basil II. Both rebels briefly joined forces, but then Bardas Phocas proclaimed himself emperor on 14 September 987. Basil II turned to the Kievan Rus' for assistance, even though they were considered enemies at that time. Vladimir agreed, in exchange for a marital tie; he also agreed to accept Christianity as his religion and to Christianize his people. When the wedding arrangements were settled, Vladimir dispatched 6,000 troops to the Byzantine Empire, and they helped to put down the revolt.[23]