The continuing rivalry between Byzantium and Sasanian Persia for supremacy in the Caucasus, and the unsuccessful insurrection (523) of the Georgians under Gurgen had severe consequences for the country. Thereafter, the king of Iberia had only nominal power, while the country was effectively ruled by the Persians. By the time of Vezhan Buzmihr's tenure as marzban of Iberia, the hagiographies of the period implied that the "kings" in Tbilisi had only the status of mamasakhlisi, which means "head of the (royal) house".[7] When Bakur III died in 580, the Sassanid government of Persia under Hormizd IV (578-590) seized on the opportunity to abolish the Iberian monarchy.[8] Iberia became a Persian province, administrated through its direct rule by appointed marzbans,[9][10] which in fact was, as Prof. Donald Rayfield states; "a de jure continuation of de facto abolition of Iberian kingship since the 520s".[7]