Guaram's successor, the second presiding prince Stephen I (Stephanoz I), reoriented his politics towards Persia in a quest to reunite a divided Iberia, a goal he seems to have accomplished, but this cost him his life when the Byzantine emperor Heraclius attacked Tbilisi in 626,[11] during the Byzantine–Sasanian War of 602–628, marking the definite Byzantine predominance in most of Georgia by 627-628 at the expense of the Sasanids until the Muslim conquest of Persia.[12]