Not to be confused with the Iberian Peninsula, a geographic area in south-western Europe that includes Spain, Portugal, Andorra and Gibraltar.

Kingdom of Iberia ქართლის სამეფო kartlis samepo

In Greco-Roman geography, Iberia (Ancient Greek: Ἰβηρία; Latin: Hiberia) was an exonym (foreign name) for the Georgian kingdom of Kartli (Georgian: ქართლი), known after its core province, which during Classical Antiquity and the Early Middle Ages was a significant monarchy in the Caucasus, either as an independent state or as a dependent of larger empires, notably the Sassanid and Roman empires. Iberia, centered on present-day Eastern Georgia, was bordered by Colchis in the west, Caucasian Albania in the east and Armenia in the south.

Its population, the Iberians, formed the nucleus of the Georgians (Kartvelians). Iberia, ruled by the Pharnavazid, Arsacid and Chosroid royal dynasties, together with Colchis to its west, would form the nucleus of the unified medieval Kingdom of Georgia under the Bagrationi dynasty.

In the 4th century, after the Christianization of Iberia by Saint Nino during the reign of King Mirian III, Christiantity was made the state religion of the kingdom. Starting in the early 6th century AD, the kingdom's position as a Sassanian vassal state was changed into direct Persian rule. In 580, king 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).

The term "Caucasian Iberia" is used to distinguish it from the Iberian Peninsula in Western Europe.
The provenance of the name "Iberia" is unclear. One theory on the etymology of the name Iberia, proposed by Giorgi Melikishvili, was that it was derived from the contemporary Armenian designation for Georgia, Virkʿ (Armenian: Վիրք, and Ivirkʿ [Իվիրք] and Iverkʿ [Իվերք]), which itself was connected to the word Sver (or Svir), the Kartvelian designation for Georgians. The letter "s" in this instance served as a prefix for the root word "Ver" (or "Vir"). Accordingly, in following Ivane Javakhishvili's theory, the ethnic designation of "Sber", a variant of Sver, was derived from the word "Hber" ("Hver") (and thus Iberia) and the Armenian variants, Veria and Viria.According to another theory, it is derived from a Colchian word, "Imer", meaning "country on the other side of the mountain", that is of the Likhi Range, which divided Colchis and Iberia from each other.

Flag of the kingdom after Christianization of Iberia in an early 4th century



https://en.wikipedia.org/wiki/Kingdom_of_Iberia