The Parthian wars of Septimius Severus

Having served c. AD180 as legatus of Legio IV Scythica at Zeugma, Septimius Severus returned to Syria in 194 to confront Pescennius Niger who had proclaimed himself emperor at Antioch in the previous year. 107 It seems that the kings of Osrhoene and Hatra had supported Niger, and the Parthians had taken advantage of the civil war to strengthen their influence in the region. These were the motives for Severus’ campaigns in Osrhoene and Mesopotamia, and later against Hatra. Severus took control of Syria quickly and in 195 successfully campaigned against the Parthians in Mesopotamia where forces from Osrhoene, Adiabene and the Arabians (probably Hatra) had begun to besiege Nisibis. It seems that the Edessan king in particular had conspired to rid the kingdom of Roman control by taking advantage of the civil war between Septimius Severus and Pescennius Niger. The siege of Nisibis indicates that it was under Roman military control at this time, but it is difficult to estimate how much earlier this had taken place.

The result of Severus’ first Parthian campaign was the conversion of part of the kingdom of Osrhoene into a Roman province and the retention of a client-kingdom at Edessa based on a much reduced portion of the former kingdom. Severus prosecuted a second and more significant war against the Parthians in 197-198 in response to an attack on Mesopotamia in which Nisibis had almost fallen. Once successful in Mesopotamia, Severus invaded Parthia, marched down the Euphrates and captured Babylon and Seleucia-Ctesiphon. The emperor attacked Hatra on his return from Parthia late in 198 or early in 199, and again in 200; but he was unsuccessful in both cases.

The important outcomes of Severus’ campaigns in the 190s included the formation of the province of Mesopotamia, the establishment of the province of Osrhoene and the creation of the dependent kingdom of Edessa. Important also was the division of Syria into the two provinces of Coele Syria and Syria Phoenice. The northern half of the old province of Syria constituted Coele Syria and it was in this new, smaller province that the stretch of the Euphrates from Samosata to Dura Europos flowed. The city of Palmyra, more closely linked with the Euphrates through cities such as Dura Europos in Coele Syria, actually became a part of the province of Syria Phoenice. It has also been argued recently that the kingdom of Hatra formed an alliance with Rome soon after the unsuccessful Severan attempts to capture it, but the evidence for such an alliance is not clear until the 230s.

The province of Mesopotamia occupied the area of northern Mesopotamia. It lay to the east of the new province of Osrhoene and the client-kingdom of Edessa, across the Khabur river and as far east as the upper Tigris. The inclusion of much of the Khabur river in the province of Mesopotamia in the third century AD is indicated by a papyrus of 245 from a village thought to be near modern Hasseke, located just to the west of the Khabur. The papyrus is a petition from a villager to Julius Priscus who is named as Praefectus Mesopotamiae, indicating that he had jurisdiction over this section of the Khabur. This is thought to reflect the situation at the time of the province’s formation 50 years earlier.

The province of Mesopotamia was created by 198 and received two of three newly raised Parthian legions. Both legions seem to have been established there after the first war of 194/195, I Parthica at Singara and III Parthica probably at Nisibis. The coloniae and major cities/fortresses of the new province were Nisibis, Singara and Rhesaina. The province was governed by a praefectus of equestrian rank, and its garrison of two legions – the same number as Coele Syria – demonstrates the military and defensive role it was designed to play. The formation of the province took Roman administration and a permanent military presence further east than it had ever been before. It is true that Trajan had established a short-lived province of Mesopotamia approximately 80 years earlier, and from the mid-160s Mesopotamia perhaps experienced a Roman military presence, but Severus’ establishment of the province was a long-term undertaking. According to Dio, Septimius Severus said that he had gained this territory in order to make it a bulwark for Syria. Dio’s report of Severus’ claim is telling with regard to the longer-term significance of Mesopotamia following its formation. Increased power and authority in Syria resulted in the third century. This is the context in which the Roman military presence on the middle Euphrates and Khabur rivers needs to be considered. Dio was ultimately critical of the move because Rome had taken control of more territory that had been traditionally Parthian and this led to the empire becoming even more embroiled in wars and disputes with its eastern neighbour.

It is difficult to be precise about the territory encompassed by Mesopotamia as precision seems not to have existed in antiquity. Roman texts referring to Mesopotamia before the last years of the second century do not always mention the area that would become the province of Mesopotamia from Severus’ reign. In the second half of the first century AD, for example, Pliny the Elder located what he called the Prefecture of Mesopotamia in the western portion of what was then the kingdom of Osrhoene, containing the principal towns of Anthemusia and Nicephorium. Singara, which would form an important legionary base in the province of Mesopotamia under Septimius Severus and later emperors, was described in the same passage by Pliny as the capital of an Arabian tribe called the Praetavi. The province of Mesopotamia in the early third century comprised quite different territory to the earlier descriptions, but it probably bore similarities to its definition under Trajan. Lucian of Samosata, however, complained that contemporary writers in the 160s were so ill-informed about Mesopotamia and where it lay that they made serious errors in locating it and the cities it contained. Some precision, however, can be established. The area that comprised the province was focused on the important cities of Nisibis, Singara and Rhesaina, and part of the Khabur river lay within the province.

In the years between Septimius Severus’ reorganization of the eastern provinces and events late in the reign of Severus Alexander, the most significant developments relevant to Coele Syria, Osrhoene and Mesopotamia took place in the reign of Septimius Severus’ son Caracalla. In 212/213, the client-kingdom of Edessa was itself abolished and became part of the province of Osrhoene, with the city of Edessa becoming a Roman colonia. The provincial reorganization set in train following the territorial gains of Septimius Severus was for now complete. There were two provinces across the Euphrates and one of them lay on a section of the upper Tigris.

In 216, Caracalla, like his father, resolved on a Parthian campaign. This took him across the Tigris to Arbela before his murder near Edessa in 217. Caracalla’s short-lived successor Macrinus met with defeat at the hands of the Parthian king Artabanus V at Nisibis, but Mesopotamia remained under Roman control. The growing Sasanian challenge to the Parthians was developing, which may be reflected in the inability of Artabanus to press his victory in Mesopotamia. It was not until after the Sasanian overthrow of the Parthians was complete that Roman power in Mesopotamia and on the middle Euphrates would be seriously challenged.

Battle of Nisibis

After Caracalla’s assassination, his successor Macrinus (217-18) immediately announced that his predecessor had done wrong by the Parthians and restored peace. In 218, after a battle fought at Nisibis during which both sides suffered heavy losses, a treaty was signed. According to Herodian, the Roman emperor Macrinus was delighted about having won the Iranian opponent as a reliable friend.

Near the city of Nisibis in Mesopotamia, an army led by Parthian King Artabatus V clashed with the legions of Emperor Macrinus. Following a skirmish between opposing troops over control of a water source, the two armies assembled for battle. The Parthian host consisted of large formations of heavy cavalry – both clibanarii and cataphracti – light mounted bowmen and a contingent of armoured camel riders called dromedarii. Macrinus readied his army for battle across the plain: the legions deployed in the centre, with cavalry and Moorish troops placed on the flanks. Arrayed at intervals within the central formation were Moroccan auxilia. Once battle was joined, the Parthian heavy horse and mounted archers inflicted severe casualties on the Roman infantry, while the legionaries and light troops proved superior in all hand-to-hand action. As the contest wore on, the Romans found themselves increasingly at a disadvantage against the speed and manoeuvrability of the enemy cavalry. In an effort to disrupt these incessant attacks, the legions feigned retreat at one point so as to draw the horsemen onto ground littered with caltrops and other devices designed to cripple the horses. Fighting continued unabated until dusk. Battle resumed the next morning and lasted all day, but again ended at nightfall with no clear victor. On the third day, Artabatus attempted to use his superior numbers of cavalry to encircle the Roman formation by means of a double envelopment, but Macrinus extended his battle-line in order to thwart the Parthians’ efforts. Toward late afternoon, the Roman emperor sent envoys to treat for peace, which was readily granted by the king. Artabatus afterward returned to Persia with his army, and Macrinus and his forces withdrew to the city of Antioch in Syria. To deter a resumption of hostilities, Macrinus presented the Parthian ruler with gifts amounting to 200 million sesterces.

Camel Cataphracts

Like most Parthian armies, the forces under Artabanus consisted mostly of cavalrymen and archers. On the other hand, the Parthian army at Nisibis was unique in that it contained a contingent of a rare cataphract–type of warriors who were mounted not upon horses, but rather camels instead. In his History of the Roman Empire, Herodian first mentions the distinctive troops in the events leading up to the battle:

Artabanus was marching toward the Romans with a huge army, including a strong cavalry contingent and a powerful unit of archers and those cataphracts who hurl spears from camels.

The camel cataphracts fought with either spears or lances, and both riders and mounts wore extensive armour like the traditional cataphracts who rode horses. Along with the legionaries, the Roman army also included contingents of light infantry and Mauretanian cavalrymen. The fighting between the two ancient superpowers was brutal and lasted for three long days. Herodian recorded how deadly the Parthian warriors, including the camel cataphracts, were on the first day of the fighting, yet he also described how the Romans eventually managed to gain the upper hand:

The barbarians inflicted many wounds upon the Romans from above, and did considerable damage by the showers of arrows and the long spears of the cataphract camel riders. But when the fighting came to close quarters, the Romans easily defeated the barbarians; for when the swarms of Parthian cavalry and hordes of camel riders were mauling them, the Romans pretended to retreat and then they threw down caltrops and other keen–pointed iron devices. Covered by the sand, these were invisible to the horsemen and the camel riders and were fatal to the animals. The horses, and particularly the tender–footed camels, stepped on these devices and, falling, threw their riders. As long as they are mounted on horses and camels, the barbarians in those regions fight bravely, but if they dismount or are thrown, they are very easily captured; they cannot stand up to hand–to–hand fighting. And, if they find it necessary to flee or pursue, the long robes which hang loosely about their feet trip them up.

However, with the coming of night and no clear victor to the battle, the two armies retreated to their camps to rest for the night. The second day of the fighting ended in a stalemate as well. The third day of the battle, however, decided the outcome when the Parthians changed their tactics to try and fully envelope the numerically inferior Roman force. In response to the encircling attempts of the Parthian soldiers, the Romans extended their own lines to compensate for the extended Parthian front. However, the Parthians were able to exploit the weakened thinner lines of the Romans and achieve a great victory. Knowing he had lost the battle, Emperor Macrinus retreated and, soon after, his men fled to the Roman camp as well. Although the Parthians won the Battle of Nisibis, it was a Pyrrhic victory for Artabanus; the losses were heavy for both sides. Since the Parthian emperor desired peace almost as much as Macrinus, Artabanus accepted only a substantial payment in return for a cessation of hostilities, as opposed to the territory he previously demanded.

Although Emperor Macrinus was quickly defeated, executed and replaced by one of his rivals, Elagabalus (r. 218-222), in 218, the Roman Empire continued to persist for centuries following its defeat at Nisibis. The Parthian Empire, on the other hand, became even weaker after its conflict with Rome and continued on its steady decline. Revolts from within the empire continued to plague Artabanus so he could not sit back and enjoy his success over the Romans. In 220, the leader of the Persians, Ardashir, managed to break free from Parthian rule and exploit the weakness of the empire to extend his control over more and more land. By 224, Artabanus met Ardashir on the field of battle and lost more than his life; the Parthian Empire collapsed shortly after his fall. In place of the Parthians, a resurgent Persian state arose known as the Sassanian Empire. As the new supreme empire of the east, the armies of the Sassanians had some of the greatest warriors of the ancient world. Like its Parthian predecessor, the elite heavy cavalry of the Sassanian Empire were also cataphracts.


Emperor from 217 to 218, and a one-time PREFECT OF THE PRAETORIAN GUARD under Caracalla, whose death he masterminded. He was born to a poor family in Caesarea, in Mauretania, and many details of his life have not been verified, but he apparently moved to Rome and acquired a position as advisor on law and finances to the Praetorian prefect Plautianus. Surviving the fall of the prefect in 205, Macrinus became financial minister to Septimius Severus and of the Flaminian Way. By 212, Macrinus held the trust of Emperor Caracalla and was appointed prefect of the Praetorian Guard, sharing his duties with Oclatinus Adventus. Campaigning with Caracalla in 216 against the Parthians, Macrinus came to fear for his own safety, as Caracalla could be murderous. When letters addressed to the emperor seemed to point to his own doom, Macrinus engineered a conspiracy that ended in early 217 with Caracalla’s assassination near Edessa.

Feigning grief and surprise, Macrinus manipulated the legions into proclaiming him emperor. To ensure their devotion and to assuage any doubts as to his complicity in the murder, he deified the martially popular Caracalla. Meanwhile, the Senate, which had come to loathe the emperor, granted full approval to Macrinus’ claims. The Senate’s enthusiasm was dampened, however, by Macrinus’ appointments, including Adventus as city prefect and Ulpius Julianus and Julianus Nestor as prefects of the Guard. Adventus was too old and unqualified, while the two prefects and Adventus had been heads of the feared FRUMENTARII.

Real problems, both military and political, soon surfaced. Artabanus V had invaded Mesopotamia, and the resulting battle of Nisibis did not resolve matters. Unable to push his troops, whom he did not trust, Macrinus accepted a humiliating peace. This, unfortunately, coincided with plotting by Caracalla’s Syrian family, headed by JULIA MAESA. Macrinus had tried to create dynastic stability, but mutiny in the Syrian legions threatened his survival. The Severans put up the young Elagabalus, high priest of the Sun God at Emesa, as the rival for the throne. Macrinus sent his prefect Ulpius against the Severan forces only to have him betrayed and murdered. He then faced Elagabalus’ army, led by the eunuch Gannys, and lost. Macrinus fled to Antioch and tried to escape to the West but was captured at Chalcedon and returned to Antioch. Both Macrinus and his son DIADUMENIANUS, whom he had declared his coruler, were executed.

The reign of Macrinus was important in that it was the first time that a nonsenator and a Mauretanian had occupied the throne. Further, he could be called the first of the soldier emperors who would dominate the chaotic 3rd century A. D. As his successors would discover, the loyalty of the legions was crucial, more important in some ways than the support of the rest of the Roman Empire.


A strategically important city in Mesopotamia, between the upper reaches of the Tigris and Euphrates rivers. Nisibis was for many centuries the capital of the district of Mygdonia, situated on the Mygdonius River. Few cities were so bitterly involved in the conflicts between Rome and the empires of PARTHIA and PERSIA. Any advance into Mesopotamia from Armenia would aim for the occupation of Nisibis to allow a further attack against the Tigris or south into Mesopotamia and the Euphrates satrapies. In his campaign against Parthia, Emperor Trajan captured Nisibis in 114 but then lost it in the revolt of 116 that killed his general Maximus Santra. The reliable Moor, Lusius Quietus, was unleashed, and he retook Nisibis as well as EDESSA. Emperor Septimius Severus suppressed an uprising of the Osroene in 194 and created a colony at Nisibis, providing it with a procurator. Upon his return in 198, Severus decreed MESOPOTAMIA a province, with Nisibis as its capital and the seat of an Equestrian prefect who controlled two legions.

Throughout the 3rd century A. D., Nisibis was buffeted back and forth as Rome and Persia struggled against one another. Following the crushing defeat of King NARSES in 298, at the hands of Emperor Galerius, Nisibis enjoyed a monopoly as the trading center between the two realms. In 363, Julian launched an unsuccessful Persian expedition; his successor Jovian accepted a humiliating peace with SHAPUR Nisibis became Persian once again.

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