Vladimir the Great
Kiev Princes were often married into the Byzantine imperial family and Constantinople often employed Princes' armies, most notably Vladimir the Great presented Byzantine with the famous Varangian Guard – an army of vicious Scandinavian mercenaries. Some believe that it was done in exchange for the marriage to Basil's sister, "porphyrogenita" Anna to Vladimir the Great. However, as Primary Chronicle states the marriage was in exchange for the Rus conversion to Orthodoxy, the creation of the Varangian Guard, although significant, was only a by-product of this exchange.