Siege of Nisibis
573 CE.
Shown on the map at 37.083°, 41.217°.
The Siege of Nisibis took place in 573 when the Byzantine Empire, under Emperor Justin II, besieged the Sasanian city of Nisibis. The Sasanians successfully defended the city and defeated the Roman force. In line with their tactics during the Iberian War, the Romans mobilized garrisoned engineers for the attack and ordered them to perform complex siege. According to the Syriac chronicles, the Sasanian forces were able to delay the Roman army, allowing them to prepare for an extensive defence. The reason behind the Roman rout at Nisibis was reportedly due to quarreling amongst their officers. An account also cited a failure of intelligence from Ghassanid scouts, due to which the Romans were unaware of the Sasanian army's movements to the Euphrates junction with the Khabur, which then attacked from the rear, forcing them to lift the siege. After the siege was lifted, the Sasanians used the Roman trebuchets that were left behind at the successful Siege of Dara, later that year. This particular siege lasted six months and the victory gave Khosrow I another important fortress in eastern Mesopotamia.
Text from the Wikipedia article Siege of Nisibis (573), licensed CC BY-SA 4.0.