Parthamasiris was not the grandest ruler in the history of Armenia – he occupied the Armenian throne for only twelve months and was unable to realize his state ambitions. Or maybe, he did not even have time to formulate a plan for the development of the country.
In the first year of the reign of unfortunate Partamasir, the formidable emperor Trajan invaded the Armenian capital and expelled the king from the palace. The Roman conqueror spared the life of the ex-ruler but set a strict condition – Partamasir was to leave the Armenian capital Artashat and stay away from the borders of Greater Armenia.
The dethroned Armenian king attempted to escape from the Romans but was arrested and after some time brutally executed by the order of Trajan.
The fateful year of 114 became the last in Parthamasiris’ life. Whether this life was short or long is unknown since the year of birth of the Armenian king is hidden in the darkness of history. But it is known for certain that Parthamasiris was a prince of royal blood and became a victim of court political intrigues between two neighboring empires – Parthia and Rome.
At that time, the rulers of Greater Armenia were approved by the Roman Emperor. Parthamasiris was the youngest son of the Parthian king Pacorus II and could not claim the Armenian throne since his elder brother Ashkhadar, a protege of Rome, was already seated in the royal palace. The candidacy of Ashkhadar was approved personally by Trajan.
The relations between the countries were becoming warmer thanks to the so-called Randea peace treaty concluded in 62 between Rome, Parthia, and Armenia after exhausting wars. According to this treaty, all three parties were to make mutual concessions provided that the Armenian kings would receive the crown of Armenia from the hands of the Roman emperor.
It is clear that only Rome was happy with this alignment. The struggle for power in Armenia was serious as well.
In 113, the Parthian emperor Khosrov I decided to take revenge and carried out a coup in Armenia. He ousted the Roman protege Ashkhadar from the throne and replaced him with his protege Parthamasiris. Both kings, as we already know, were sons of the Parthian king Pacorus II who had died in 105.
Considering the actions of the Parthian king as a violation of the Randea agreement, Trajan declared war against Armenia and Parthia. In 114, Roman troops entered Armenia and marched towards Artashat.
Parthamasiris was unable to organize worthy resistance and was deposed, and Armenia became a Roman province. Though not for long – just a couple of years.
Already in 117, the new Roman emperor Hadrian allowed the Armenians to have their king and enthroned Vagharsh I (117–140) from the Arshakuni dynasty. This king founded the new city of Vagharshapat and transferred his residence to it from Artashat.