First Christian king of Iberia (East Georgia), founder of the Chosroid dynasty; b. c. 282; d. 361. As a member of the House of Mihran, one of the seven great houses of the Iranian monarchy, he was placed on the throne of Iberia by the Iranians, who were anxious to counterbalance Roman influence in Armenia. At about age seven (c. 289), he passed through a ceremony of marriage with Abeshura, the Arsacid heiress of Iberia. Converted to Christianity in middle age by the preaching of St. Nino (334), he sent to the Emperor Constantine for priests, and in 337 he was baptized together with his people. Though Iberia was an area traditionally under the jurisdiction of Antioch, John, the first bishop of Iberia, was sent from Constantinople because of the Emperor Constantine's war with Iran, begun in 337. Mirian is venerated as a saint by the Georgian Church.
Bibliography: m. tamarati, L'Église géorgienne: Des origines jusqu'à nos jours (Rome 1910). c. toumanoff, Studies in Christian Caucasian History (Washington 1963).