# Siege of Nisibis (350)

The Third siege of Nisibis in 350 AD is yet another unsuccessful attempt at regaining the city of Nisibis (modern Nusaybin) by the Sassanid "king of kings" (Shahanshah) Shapur II.

## Prelude

In 335, During the Perso-Roman wars of 337–361, Emperor Constantine sent his son Constantius in preparation for a campaign against the Sasanid Empire. Constantius recruited and drafted new soldiers, implemented training and drills, expanded the cavalry, and stockpiled supplies. These preparations did not go unnoticed by the Sasanids. In 336, Shapur II sent his general Narses to invade Armenia. Narses, however, was later defeated and killed in Narasara. Following Constantine the Great's death, Shapur besieged Nisibis, which was then regarded as the key to Mesopotamia. After sixty or seventy days, no closer to taking Nisibis and with a plague hampering his army, he lifted the siege and returned to Persia. Although he lost at Nisibis, Shapur collected tribute from the Armenian king Khosrov starting in the year 345–6.
In 343–4, Constantius met Shapur's forces near Singara. The date of this battle is uncertain. Sources are divided as to the victor of the battle. Some sources state a Sasanian victory, some a Roman victory, while another states a pyrrhic Roman victory.

## The siege

The third siege of the city in 350 AD was by far the most determined attempt by Shapur II to gain a foothold in northern Mesopotamia, and consequently the most fierce of the three sieges. It is also the best documented of the three sieges. Of our sources, the most spectacular account is given by the Emperor Julian in his two panegyrics on his imperial cousin, the Emperor Constantius II.
Shapur is said to have surrounded the city with dykes, then imitating the Persian kings of old, he diverted the Mygdonius and created an artificial lake around the city. The Persians then mounted siege engines on boats but the stalwart defenders managed to haul up some of them, and set others on fire. Such a description of a “sea battle on dry land,” as Libanius called it, pushes the modern scholar to the limits of credulity. For the towers of Nisibis to be “just visible” above the waters, as Julian would have his readers believe, the earthen mound needed to hold the floodwater would have to be of enormous strength and height.
Furthermore, there are some similarities between Julian’s account of the siege of Nisibis and a contemporary account of the siege of Syene in a work of romantic fiction, the Aethiopica of Heliodorus. The latter also describes a siege conducted from ships. On the other hand, Ephrem who would have been an eyewitness to the third siege of Nisibis, as he was a teacher in the local school, in his Carmina Nisibena (composed in celebration of the divine protection of the city), made numerous references to floodwater and dykes.
Meanwhile, the dams of the river Mygdonius, which passed near the valley in which Nisibis was located, were broken down, and the valley flooded. When the whole plain was filled with water up to the walls of the city, a Sasanid fleet was embarked and floated to the ramparts. A part of the walls collapsed and the Sasanids withdrew in preparation for the assault. The attack which was launched, supported by Sassanid war elephants, bogged down in the muddy waters formed by the lake, and Shapur gave the signal to fall back. One of the assault tactics deployed during the Sasanian era is the three-wave attack implemented during the siege of Nisibis in 350 AD. Julian reports the first wave as having been lance-bearing armored cavalry followed by archers who would be (the third wave) of another contingent of armored cavalry lancers. The "archers" were presumably mounted to keep pace with the armored cavalry. The primary advantage of this tactic was that it forced defending infantry to rapidly "switch" their tactics in order to adapt to each type of (lance or missile) assault. In the interval of a single night the defenders effected the repair of the walls, this along with news of Hunnic invasions of the eastern provinces, compelled Shapur to a cessation of hostilities against Rome.

## Consequences

Before retreating to Persia, Shapur burned all his siege equipment and executed some of his chief officers and advisors.
Nisibis, after having successfully resited Sasanian attacks three times, was nominated the "Shield of the Empire" by Zonaras, and with that the Siege of Nisibis in 350 AD was over, risulting in a Roman victory, and a lifting of the siege by Shapur, after suffering heavy losses, probably amounting up to 20,000.
The presumed commander of the defense of the city, Lucillianus, was awarded, according to Seeck, the rank of dux Mesopotamiae, but the authors of the PLRE found comes rei militaris more likely. Lucillianus's superior in rank was the magister equitum, Ursicinus.