In Greco-Roman geography, Iberia (Ancient Greek: Ἰβηρία Iberia; Latin: Hiberia; Parthian: wurğān; Middle Persian: wiručān) was an exonym for the Georgian kingdom of Kartli or kingdom of Iveria (Georgian: ქართლის სამეფო ან ივერიის სამეფო), known after its core province, which during Classical Antiquity and the Early Middle Ages was a monarchy in the Caucasus, either as an independent state or as a dependent of larger empires, notably the Sassanid and Roman empires.

Starting in the early 6th century AD, the kingdom's position as a Sassanian vassal state was changed into direct Persian rule.

The written sources for the early periods of Iberia's history are mostly medieval Georgian chronicles, that modern scholarship interpret as a semi-legendary narrative.

[21] One such chronicle, Moktsevay Kartlisay (“Conversion of Kartli”) mentions that a ruler named Azo and his people came from Arian-Kartli – the initial home of the proto-Iberians, which had been under Achaemenid rule until the fall of the Persian Empire – and settled on the site where Mtskheta was to be founded.

Pharnavaz is also said to have built a major citadel, the Armaztsikhe, and a temple to the god Armazi, and to have created a new system of administration, subdividing the country into several counties called saeristavos.

However, it was only under Hadrian's successor Antoninus Pius that relations improved to the extent that Pharsman is said to have even visited Rome, where Dio Cassius reports that a statue was erected in his honor and that rights to sacrifice were given.

Excavation of rich burials in Bori, Armazi, and Zguderi has produced silver drinking cups with the impression of a horse either standing at a fire-altar or with its right foreleg raised above the altar.

was introduced by King Pharnavaz in the 3rd century BC (connected by the medieval Georgian chronicle to Zoroastrianism)[31] Decisive for the future history of Iberia was the foundation of the Sasanian (or Sassanid) Empire in 224 by Ardashir I.

Relations between the two countries seem to have been friendly at first, as Iberia cooperated in Persian campaigns against Rome, and the Iberian king Amazasp III (260–265) was listed as a high dignitary of the Sasanian realm, not a vassal who had been subdued by force of arms.

[34] Roman predominance proved crucial in religious matters, since King Mirian III and leading nobles converted to Christianity around 317 and declared as state religion.

The event is related with the mission of a Cappadocian woman, Saint Nino, who since 303 had preached Christianity in the Georgian kingdom of Iberia (Eastern Georgia).

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.

[38] 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.

But Emperor Heraclius's offensive in 627 and 628 brought victory over the Georgians and Persians and ensured Byzantine predominance in western and eastern Georgia until the invasion of the Caucasus by the Arabs.

[40] The Arabs reached Iberia about 645 and forced its eristavi (prince), Stephanoz II (637 – c. 650), to abandon his allegiance to Byzantium and recognize the Caliph as his suzerain.

At the beginning of the 9th century, eristavi Ashot I (813–830) of the new Bagrationi dynasty, from his base in southwestern Georgia, took advantage of the weakening of the Arab rule to establish himself as hereditary prince (with the Byzantine title kouropalates) of Iberia.