Following the assassination of his father in 374, as Vologases and Arsaces III and his brother were too young to rule, the Roman emperor Valens had sent their paternal first cousin Varasdates (Varazdat) to occupy the Armenian throne.
Their cousin who was a young man highly reputed for his mental and physical gifts had lived in Rome for an unknown period of time.
Manuel raised Arsaces III and Vologases to the throne as co-kings of Armenia, under the nominal regency of their mother Zarmandukht.
Despite Armenia being the first Christian state, there were still traces of beliefs and customs in Zoroastrianism, sun worship and practices of consanguineous marriages in the country.
[17] The zeal of the Sassanid high priest Kartir established and fostered fire temples, especially in Armenia which was attested by his inscriptions.