Vologases V

During Vologases' early life, he became the ruler of Armenia, succeeding Sohaemus.[2][3][4] Throughout the 1st and 2nd-centuries, the Armenian throne was usually occupied by a close relative of the Parthian King of Kings, who held the title of "Great King of Armenia".[5][lower-alpha 1] Unlike the previous eight Arsacid princes who ruled Armenia, Vologases was able to ensure that his descendants ruled on the Armenian throne; they would rule the country until the Sasanian abolition of the Armenian throne in 428.[2]

In 189, he also imposed his son Rev I (whose mother was the sister of the Pharnavazid ruler Amazasp) on the Iberian throne.[8] His descendants would rule Iberia until 284 when it was replaced by another Parthian family, the Mihranids.[9]

In 191 after the death of his father Vologases IV, Vologases ascended the Parthian throne and passed the Armenian throne to his son Khosrov I (r. 191–217).[2][3] It is uncertain if the transition of power was peaceful or marred in a civil war.[1][10] His claim to the throne, however, was not uncontested; a rival king, Osroes II (190), had set himself up in Media even before the death of Vologases IV, but Vologases appears to have quickly put him down.[11]

Coin of the Roman emperor Septimius Severus

Vologases supported Emperor Pescennius Niger (r. 193–194) in his struggle for the Roman throne against Emperor Septimius Severus (r. 193–211) in 192–193, during the Year of the Five Emperors. Furthermore, he also intervened in the affairs of the Roman vassal states in northern Mesopotamia—Adiabene and Osroene. Because of this, Septimius Severus, who emerged victorious in the struggle, attacked the Parthian Empire in 195.[12] Severus advanced into Mesopotamia, made Osroene a Roman province, and captured the Parthian capital Ctesiphon in 199.[1][12] At the same time, revolts were occurring in the Parthian provinces of Media and Pars.[13] Septimius Severus now declared himself Parthicus Maximus ("great victor in Parthia"). He was, however, unable to maintain his conquests, due to lack of food supplies and reinforcements. As a result, he withdrew his forces; during his withdrawal, he attempted in vain to conquer the Arab fortress of Hatra twice, later withdrawing his forces to Syria.[1]

In 202, peace was restored, reaffirming Roman rule in Armenia and northern Mesopotamia.[12] But, in the words of Iranologist Touraj Daryaee, "the dynasty [had] lost much of its prestige" and reached a "turning point".[13] The kings of Persis were now unable to depend on their weakened Arsacid overlords.[13] Indeed, in 205/6, Pabag, a local ruler in Persis, rebelled and overthrew his overlord Gochihr, taking the Persis capital Istakhr for himself.[13][14] His son Ardashir I would go on to continue his conquests, overthrowing the Parthian Empire and establishing the Sasanian Empire in 224.[15]

Vologases died in 208, succeeded by his son Vologases VI (r. 208–228), however another son, Artabanus IV (r. 216–224), attempted to seize the throne a few years later, resulting in a civil war.[1][16]