[14] The great Christian sovereign then entrusted the eastern sector to his son Constantius II.

[15][16] He recruited and drafted new soldiers, including his nephew Hannibalianus, implemented training and drills, expanded the cavalry, and stockpiled supplies.

[16] It is said that already during this year, the son of the Sassanid king, Narses, managed to advance to Amida and occupy the Roman city, but shortly afterwards he was killed in battle by the advancing Roman troops[18] not far from Amida (in Narasara),[19][20] and ultimately, Constantius, with the soldiers of the Legio V Parthica and its legatus legionis,[21] was able to push back the invasion, and Shapur failed to make any significant gains.

[22] Now the location of the battle has been identified by some with Hileia or Eleia, at the foot of the Djebel Sindjar mountain range, along the Nahr Ghiran river.

[22][23] Amida, shortly after, returned to Roman hands and Constantius ordered the construction of a new and imposing circle of walls and towers, where he could also place a large artillery arsenal, thus making the city almost impregnable.