the two powers. The Georgian Principality of Iberia was in the Sassanian sphere of influence, but was Christian. Iberian bishops were sent to Antioch in the Byzantine Empire to be consecrated. Vakhtang I of Iberia was encouraged into war with the Sassanians. A "fervent Christian", his religious policies were "part and parcel of his larger strategic aims". After a lengthy struggle he was defeated and Iberia subjugated as a Sassanian province in 522. Lazica was another border state; it was Christian, but in the Sassanid sphere. Its king, Tzath, wished to reduce Sassanid influence. In 521 or 522, he went to Constantinople to receive the insignia and royal robes of kingship from Justin's hand and to make his submission. He was also baptized as a Christian and married a Byzantine noblewoman, Valeriana. After having been confirmed in his kingdom by the Byzantine emperor, he returned to Lazica. Shortly after Justin's death the Sassanids attempted to forcibly regain control, but were beaten off with assistance from Justin's successor. In 524 the Sassanid emperor Kavadh I approached Justin asking that he formally adopt his youngest son, Khosrow, in order to secure his succession over his elder, but less favoured, brothers. Justin was agreeable, but, aware that being childless himself an adopted Persian son would have a claim on the Byzantine throne, offered adoption according to barbarian custom. The Persians were insulted and broke off all negotiations. In 526, the Byzantines raided Persian Armenia at Justinian's initiative. Justinian was increasingly taking control of policy from his aging uncle. The raiding parties were led by two of Justinian's up-and-coming military protégees, Sittas and Belisarius. The raids achieved little, other than to make a statement of intent. Religion Justin's reign is noteworthy for the resolution of the Acacian schism between the eastern and western branches of the Christian church. On ascending the throne Justin invited Pope Hormisdas to Constantinople for negotiations. Justinian sent a similar, but separate, invitation; said to have been closer to a summons. Hormisdas promptly despatched a delegation to Constantinople with instructions to state the orthodox position rather than to negotiate. Carrying out a policy developed by his nephew Justinian, the future emperor, Justin endorsed Rome's view on the question of the dual nature of Christ. On 28 March 519, in the cathedral of Constantinople in the presence of a great throng of people, a reluctant Patriarch John II accepted the formula