Having removed the threat from the east, Shapur was able to resume warfare against the Romans over the control of Armenia. Armenia was one of the main reasons for the Persian and Roman wars. "The envoys were sent by Shapur, who demanded that Mesopotamia and Armenia would be returned to Persia, that they might put an end to the war with Rome; for these territories had been a source of problem to them since the time of their ancestors" (Dodgeon, 229). Shapur also stated in a letter sent to Constantius in 358 C.E., "I am bound to recover Armenia and Mesopotamia which were stolen from my grandfather (Narseh) by deliberate double-dealing" (Shayegan, 717). On the other hand, Constantine the emperor of Rome, who had converted to Christianity considered himself to be the protector of both the Romans and the Persian Christians. With Armenia and Iberia both being Christian states, Persia was Constantine's next target on the list to be converted to a Christian state with a Christian emperor. "Constantine's reply to the embassy was to prepare for war, whose aim Roman propaganda represented as the overthrow of the Sasanian monarchy and the Christianization of Persia" (p, 732). The Romans viewed Persians as barbarians characterizing them as cowards. So when Constantius crossed Tigris and captured some insignificant cities, they would send the Persians to Rome as prisoners and believe that they had saved them. .
"Then you visited the cities you had freed, and bestowed on them peace and plenty, all possible blessing and all at once. Thus at your hand they received what they had so long desired, the defeat of the barbarians.".
(Dodgeon, 180).
Born of a Jewish mother, Shapur was partial to the Jews but not to the Christians. He levied a tax on the churches and when they complained he closed them down and confiscated their property. In 310 C.E. Constantine sent a convoy to resolve matters with Shapur who was at the early stages of his reign.
