Mirian III of Iberia

Mirian III
Sarcophagus of Mirian III at Samtavro Monastery
22nd King of Iberia
Reign	284–361
Predecessor	Aspacures I of Iberia
Successor	Sauromaces II of Iberia
Born	c. 277
Died	361 Mtskheta
Burial	Samtavro Monastery, Mtskheta
Spouse	Abeshura of Iberia Nana of Iberia
Issue	Rev II of Iberia Aspacures II of Iberia Anonymous daughter
Dynasty	Chosroid dynasty
Religion	Georgian Orthodox Church

Mirian III (Georgian: მირიან III) was a king of Iberia or Kartli (Georgia), contemporaneous to the Roman emperor Constantine the Great (r. 306–337). The founder of the royal Chosroid dynasty.

According to the early medieval Georgian annals and hagiography, Mirian was the first Christian king of Iberia, converted through the ministry of Nino, a Cappadocian female missionary. He is credited with establishment of Christianity as his kingdom's state religion and is regarded by the Georgian Orthodox Church as saint and is canonized as Saint Equal to the Apostles King Mirian (Georgian: წმინდა მოციქულთასწორი მეფე მირიანი).

Traditional chronology after Prince Vakhushti assigns to Mirian's reign—taken to have lasted for 77 years—the dates 268–345, which Professor Cyril Toumanoff corrects to 284–361. He is also known to the contemporary Roman historian Ammianus Marcellinus and the medieval Armenian chronicles.

The king's name, Mirian, is a Georgian adaptation of the Iranian "Mihran". The medieval Georgian records give other versions of his name, both in its original Iranian as well as closely related Georgian forms (Mirean, Mirvan). Writing in Latin, the Roman historian Ammianus Marcellinus (XXI.6.8) renders the name of his contemporary Iberian king as Meribanes. The Armenian chronicles, possibly compiled in the 8th century and traditionally ascribed to Moses of Chorene, gives Mihran and speaks about his conversion to Christianity. The regnal numbers as in Mirian III are modern and were not used by the medieval Georgian authors. Since two kings preceded first Christian ruler of Iberia with that name, Mirian has been assigned the ordinal “III” in Georgian historiography.