Iberia is a name that the Greeks and Romans applied to Kartli, which is currently one of the administrative divisions of the modern republic of Georgia. In Hellenistic times, Iberia was a kingdom governed by the Pharnabazid Dynasty, which ruled from the dawn of the third century before Christ until late in the second century of the Christian era. According to Wikipedia, Amazasp II, the last Pharnabazid king, ruled from 185 A.D. to 189 A.D.
During the early years of Pharnabazid reign, their kingdom was uncomfortably close to the sprawling Seleucid kingdom. However, eventually the Romans took over the lands encircling the Mediterranean Sea, while the Parthians gained control over the territory now occupied by Iran and Iraq.
The Arsacid Dynasty ruled over the powerful Parthian kingdom, but by the time that the life of the last Pharnabazid king drew to a close, Parthian power was about to expire. Parthian hegemony lasted till 224 A.D., when Ardashir I, the first Sassanian ruler of Persia, led his armies against the hosts of Artabanus IV, the last Parthian king. Artabanus was killed in the ensuing battle.
In spite of the fall of Parthia, Arsacid rulers continued to enjoy power in smaller kingdoms. An Arsacid usually sat on the Armenian throne until the fifth century A.D. Arsacid rulers also enjoyed power in Albania, an ancient kingdom located in modern Azerbaijan. In addition, an Arsacid Dynasty briefly enjoyed power in Iberia.
Apparently, intermarriage between the royal houses of Armenia and Iberia facilitated dynastic change in Iberia. According to Medieval Georgian chronicles quoted by Wikipedia, the sister of Amazasp II had married an Armenian king (probably the Arsacid Vologases II). Iberian nobles revolted against Amazasp II and replaced him with Rev I, who was a son of Amazasp’s sister and the Armenian king. The Iberian nobles would have had no objection to the Arsacid Rev since he had Pharnabazid blood flowing through his veins.
A damaged inscription seems to indicate that an Amazasp of Iberia married a daughter of a Vologases of Armenia. Was the father-in-law of Amazasp also his brother-in-law? The information is too scanty to answer this question. The inscription may refer to Amazasp I of Iberia, who seems to have been more or less contemporary with Vologases I of Armenia. It is also possible that the Armenian king that married the sister of Amazasp II was not Vologases II. In fact, the Medieval Georgian chronicle might not be accurate. There are a lot of mistakes in recorded history.
At any rate, Rev I was the first king of the Arsacid Dynasty of Iberia. Not much is known about his life and reign. According to the Georgian chronicle quoted by Wikipedia, he was a pagan ruler but treated the small Christian community in his realm with kindness. He therefore was called “the Just.”
According to Wikipedia and other sources, Rev the Just ruled from 189 to 216, and the dynasty lasted from 189 to 284. Rev was succeeded by Vache (216-234), Bakur I (234-249), Mihrdat II (249-265), and Aspagur (265-284). The Georgian chronicles testify that each Arsacid ruler was the son of his predecessor, but not much more is known about these rulers. (These dates are the product of modern scholars, such as Professor Cyril Toumanoff. They differ from traditional chronology.
In addition to the Arsacid rulers recognized by the Georgian chronicle, it is thought that there may have been an anti-king named Amazasp III. He is mentioned in Sassanid inscriptions and probably was their candidate for the throne of Iberia.
The Sassanid Empire often waged war against the Roman Empire. If Mihrdat II was pro-Roman or if Shapur I, the current Sassanian king, did not like Mihrdat for some other reason, he probably would try to replace him. His success would depend in part on whether or not he was successful in his struggle with the Roman Empire.
We can only imagine what happened. However, Shapur I defeated and captured Valerian, the Roman emperor, in 260 A.D., so he had the power to install Amazasp as king of Iberia at that time. However, Odenathus of Palmyra defeated Shapur soon thereafter. I wonder how long his candidate could have maintained himself in Iberia after his patron had suffered such a serious setback.
According to Wikipedia, Aspagur was defeated by the Persians and died in exile. Mihran III, his successor, was the first king of the Chosroid dynasty. His first wife was Abeshura, the daughter of Aspagur. However, she died childless, so the successors of Mihran had no Arsacid or Pharnabazid blood in their veins.
Mihran, also known as Mirian and Meribanes, was the first Christian king of Iberia.
It is interesting to note what was happening in the Roman Empire at this time. Assuming that the dates given above are correct, Rev I came to power in the second last year of Emperor Marcus Aurelius, the last of the so called good emperors. He outlasted Commodus and Septimius Severus, and died during the reign of Caracalla. Vache witnessed the reign of Elagabalus and almost all of the reign of Alexander Severus. The last three Arsacid kings witnessed a rather chaotic period in Roman history. The reign of Aspagur ended in the same year that Diocletian came to power.
Wikipedia: Parthian Empire
History Files: Georgia
Wikipedia: King List of Georgia
Wikipedia: Pharnabazid Dynasty
Wikipedia: Amazasp II of Iberia
Wikipedia: Rev I of Iberia
Total War Center: Rome II