Siege of Nisibis
337 CE.
Shown on the map at 37.083°, 41.217°.
The siege of Nisibis of 338 constituted the initial phase of Perso-Roman wars of 337–361. Shapur besieged Nisibis, which was then regarded as the key to Mesopotamia and, after sixty days, no closer to taking Nisibis and with a plague hampering his army, he lifted the siege and returned to Persia.
Text from the Wikipedia article Siege of Nisibis (338), licensed CC BY-SA 4.0.