in 363, Rome ceded control of Iberia to Persia, and King Varaz-Bakur I (Asphagur) (363–365) became a Persian vassal, an outcome confirmed by the Peace of Acilisene in 387. However, a later ruler of Kartli, Pharsman IV (406–409), preserved his country's autonomy and ceased to pay tribute to Persia. Persia prevailed, and Sassanian kings began to appoint a viceroy (pitiaxae/bidaxae) to keep watch on their vassal. They eventually made the office hereditary in the ruling house of Lower Kartli, thus inaugurating the Kartli pitiaxate, which brought an extensive territory under its control. Although it remained a part of the kingdom of Kartli, its viceroys turned their domain into a center of Persian influence. Sasanian rulers put the Christianity of the Georgians to a severe test. They promoted the teachings of Zoroaster, and by the middle of the 5th century Zoroastrianism had become a second official religion in eastern Georgia alongside Eastern Orthodoxy. The early reign of the Iberian king Vakhtang I dubbed Gorgasali (447–502) was marked by the relative revival of the kingdom. Formally a vassal of the Persians, he secured the northern borders by subjugating the Caucasian mountaineers, and brought the adjacent western and southern Georgian lands under his control. He established an autocephalic patriarchate at Mtskheta, and made Tbilisi his capital. In 482 he led a general uprising against Persia and started a desperate war for independence that lasted for twenty years. He could not get Byzantine support and was eventually defeated, dying in battle in 502. Fall of the kingdom The continuing rivalry between Byzantium and Sasanian Persia for supremacy in the Caucasus, and the next 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. In 580, Hormizd IV (578–590) abolished the monarchy after the death of King Bakur III, and Iberia became a Persian province ruled by a marzpan (governor). Georgian nobles urged the Byzantine emperor Maurice to revive the kingdom of Iberia in 582, but in 591 Byzantium and Persia agreed to divide Iberia between them, with Tbilisi to be in Persian hands and Mtskheta to be under Byzantine control. At the beginning of the 7th century the truce between Byzantium and Persia collapsed. The Iberian Prince Stephanoz I (c. 590 – 627), decided in 607 to join forces with Persia in