The Parthian Empire, the successor of the Seleucid Empire, was a long standing rival and sometime subordinate of Rome in Asia Minor. It became the provinces of Parthia Magna in 920(167)
List of Parthian Kings and History
Appointed 14th Arsacid King in 716(-37) after the death of his brother Pacorus I, he immediately killed his father and thirty remaining brothers. His general cruelty created many enemies for him in the Parthian court.
717(-36) Failed invasion of Parthia by Marcus Antonius.
720(-33) Failed attempt by Phraates to conquer Adiabene Media, an Egyptian ally.
Early 721(-32) the prince Tiridates II was raised by the Parthians in revolt against Phraates. With Scythian aide Phraates regained the throne but Tiridates kidnapped Phraates' eldest son Phraates V and fled to Syria and Marcus Antonius. In negotiations that followed M.A. traded both Phraates V and Tiridates to Phraates IV for prisoners and Roman Eagle standards from his failed invasion.
722(-31) Second failed invasion of Parthia by M.A.
733(-20) Third failed invasion of Parthia by M.A.
722-733(-31--20) Phraates IV refrained from returning further prisoners captured from these invasions or recognising Eastern Empire superiority but also failed to capitalise on the EE apparent weaknesses.
Late 743(-10) Phraates IV murdered by his son Phraates V and one of his concubines due to Ph.IV's reluctance to assert dominance over the EE at Marcus Antonius' death and Augustus' declaration of war.
Late 743(-10) Phraates V intended to immediately strike the EE but his ascension was greeted with a three year civil war lead by Artabanus II, a prince supported by the Parthian court. Sharing the cruelty of his father, Phr.V was also better at making enemies than friends.
746(-7) Phr.V defeated Artabanus and had a substantial portion of the Parthian court assassinated, invoking further uprisings.
747(-6) Gotarzes III, a surviving noble, killed Phraates V and was elevated by the court to King.
Quite opposite to Phraates, Gotarzes was a very weak king. In 749(-4), Gotarzes sought to conquer Media Adiabene to improve his image. His preparations were marred by court intrigue and difficulty in solidifying power.
750(-3) Media abandoned its alliance with the EE after catching wind of Gotarzes' intentions. The EE is getting its ass handed to it, anyway, so best to cut ties with them now.
Early 755(2) Gotarzes began his invasion of Media.
756(3) With the EE conquered by Augustus, Gotarzes sent several sons (Gotarzes IV, Sanatruces II, and Mithradetes IV) to Rome as hostages for a treaty accepting Parthia's conquest of Media and recognising Roman superiority.
757(4) conquest of Media completed.
760(7) Gotarzes was assassinated by an unknown assailant.
The Parthian court appealed to Augustus for a new king, Sanatruces was sent back to Parthia to take the throne. However, he was soon despised for his Roman affluence; denounced and declared a Roman slave.
763(10)-766(13) Prince Artabanus III raised by the nobility to take over the throne while simultaneously another vassal noble from the east called Jahangir tried to found a new dynasty and conquer Parthia.
766(13) Sanatruces succeeded in defeating Jahangir, but forced to flee to Syria by Artabanus; "Back to his Roman mothers and whores" and all that jazz. Carico was too busy with the Imperial Succession War to care.
Artabanus III and Mithradetes IV
766(13)-792(39) & 792(39) 26&<1
766(13) Artabanus was recognised by the court as Parthian king but guess what he was also cruel. Coming from a nomadic background and education, Artabanus was unrefined and lacked political finesse; he killed a lot of the court trying to strengthen his position; rebellions followed.
By 791(38) Artabanus learned how to rule properly and things for Parthia stabilised such that Artabanus desired to force Rome to rethink its position on Parthia and to take it seriously again. Invading Armenia, Carico immediately retaliated and succeeded in driving the Parthians both out of Armenia and Mesopotamia.
792(39) Outside of Ctesiphon negotiations for peace were started, again recognising Armenia and now also Media as being under the Roman sphere. Artabanus was deposed (and later killed) and Mithradetes IV (Gotarzes III's youngest) was sent to be Parthia's king. However, within the year Mithradetes was ousted for being too Roman and instead Carico agreed to have the Parthian noble Osroes I elevated.
Though not a proponent of Rome, Osroes concluded the unfavourable peace as Parthia had quickly become too weak to properly match Rome. He was a moderate ruler, and managed to maintain the support of the nobles. His 20 year old son Osroes II succeeded him with the acquiescence of both the court and Rome.
Osroes II proved quite competent a king, and under him Parthia began to recover and compensate for the loss of fertile Mesopotamia. In fact during the reign of Domitian in Rome the Parthian court began to urge Osroes to retake Mesopotamia when Rome showed incompetence in its war against the Dacians (842-3(89-90)). With Domitian's assassination and the war's conclusion the Parthian court became adamant, but when Nerva was elected Cæsar and soon came to renew the 792(39) peace, Osroes thought the matter closed. Osroes had already been equally adamant that Parthia could not contest Rome in his lifetime, and the Parthian court proved him correct.
Lexamizd, a noble with Armenian ancestry and a strong military background, was elevated by the court over Nerva's suggestion of Vonones II, but Nerva let this slide as he was very busy with internal maintenance. The revolt of Assyria and Ctesiphon itself the next year was violent, and Lexamizd along with other Parthian princes ignominiously died as the court evacuated to Ecbatana.
So chaotic was the aftermath of the war with Rome and Assyria's revolution, the Romans did not even bother appointing a king for the Parthians and it took a full year for them to agree on one themselves. The prince Arsak was renamed Phraates VI and spent his entire reign just trying to maintain and stabilise the empire. His nephew Artabanus IV was elevated to king upon his uncle's death.
Artabanus IV was a miracle worker; the 24th and final Arsacid King. He had immense respect from the nobility, a high education, and intelligence. He was a Lexamizd and Osroes II combined. He reforged trade with India and Sinica, culture thrived, and the military was reformed with some Roman inspiration.
By 914(161), however, he had lost his head, and began making demands of Rome to return Mesopotamia and Assyria, which were ignored, Rome hadn't recognised Artabanus as the new king, anyway. They hardly viewed Parthia as a great power anymore, and encountering this attitude Artabanus invaded Mesopotamia in 915(162), expecting to encircle and convince Assyria to turn against Rome. Although no longer considered a great power, the standing tradition of having competent generals in the east was not dropped, and Artabanus was singled out in his invasion and killed in the very first set battle. Despite having brought up good generals for the Parthian side, the late Artabanus' forces were overwhelmed, routed, and ultimately run down as the new province of Parthia emerged behind the boots of the invading legions.