For centuries after the reign of Augustus, the eastern frontier of the Roman Empire south of the Taurus Mountains had rested upon the western bank of the Euphrates River. North of the Taurus, the kingdom of Armenia had been Rome’s neighbor. Control of that realm had been negotiated with the Arsacid kings of Parthia so that their nominee to the throne had to be approved by the Roman emperor. The province of Syria had more than once been home to pretenders to the Arsacid throne in Ctesiphon. The arrangement with Parthia had enabled Rome to maintain control of the east with an army of six legions in the time of Marcus Aurelius. Three of these legions were concentrated in Syria, where the main threat could be expected; one was relatively isolated at Melitene in Commagene, while the other two formed the garrison of Arabia, with responsibility for patrolling the desert as well as supporting the garrison of Syria. Rome counted on having ample advance warning of Parthian maneuvers, and might reasonably have expected that no Parthian army could have been larger than the roughly 30,000 men who could be supplied on campaign. The successful invasion of the Parthian kingdom that Trajan carried out in the last years of his life may also have suggested that the balance of power had shifted irretrievably in favor of Rome.
Parthian armies appear to have consisted largely of horse archers and heavy cavalry, and to have been raised with difficulty. The Parthian empire was divided into a number of subsidiary kingdoms whose rulers were ordinarily relatives of the king (Frye 1984: 217-33). It appears that the king depended upon these subsidiary rulers to provide troops when he needed them. Often they seem to have been fractious and disloyal. When content and properly commanded, however, they were not inconsequential.
Seven years after the war with Macrinus, the Parthian regime was swept away by a new dynasty from the province of Fars in southern Iran. Fars was the ancestral home of the ancient Achaemenid kings, and seems to have remained a center for the cult of Ahura Mazda and the Zoroastrian priesthood. The regime that replaced the Arsacids, founded by Ardashir, proved to be vastly more effective in mobilizing its forces, and driven by religious zealotry. Ardashir saw himself as the servant of Ahura Mazda, and his foes as the servants of Ahriman, the embodiment of evil.
The Roman response to the rise of Ardashir was marked by incomprehension and fantasy. Both Cassius Dio and Herodian write of Ardashir as a man who was motivated by the desire to regain the ancient empire of the Achaemenids, a view that is utterly without support in third-century Sasanian texts (Kettenhoffen 1984: 177-90;
Potter 1990: 370-80). At best, the advisors of Severus Alexander may have seen the Sasanian revolution as just one more manifestation of the endemic instability of the Parthian kingdom. As a result they opened the door to refugees from the old regime, supported the Arsacid king of Armenia as a client, and received the Arab city of Hatra as a protectorate. Although Ardashir’s primary interest appears to have been to solidify the position of his own extended family as the royal family in the empire - members of the Sasanian clan replaced Arsacids wherever Ardashir could arrange it - Alexander’s advisors could not see that by supporting Arsacid survivors they were inviting conflict.
Ardashir began to raid Roman territory almost immediately after he had taken power at Ctesiphon, making Roman armies look plodding and inept. When Alexander launched a massive invasion of his territory in the early 230s, Ardashir drove it back, inflicting heavy casualties. In 235 he captured the cities of Nisibis and Carrhae, giving him control of the easiest invasion route across northern Mesopotamia and effectively ruining the frontier arrangements established by Septimius Severus, who had created a Roman province that extended across northern Mesopotamia to the Tigris (Kettenhoffen 1995: 159-77). In 241, Ardashir destroyed the city of Hatra, and turned over the throne (we do not know whether he died or abdicated) to his son, Sapor I (Potter 1990: 190).
It had been centuries since the Roman state confronted an enemy as deadly and determined as Sapor proved to be. It is arguable that he was a general whose skill was comparable to that of Hannibal, for like Hannibal he seems to have proceeded from a careful study of the Roman way of war, and the disasters that he inflicted on Roman armies were on a par with some of the great catastrophes suffered at the beginning of the Second Punic War. His armies, like those of his father, also possessed a skill at siege warfare that appears to have been absent from the armies ofthe Parthian kingdom. The record of Sasanian success against places like Hatra (which had withstood a siege by Septimius Severus), Carrhae, and Nisibis is impressive enough; archaeological evidence from Dura Europus reveals that the Sasanians had engineers capable of sophisticated operations including tunneling beneath the walls of cities. This was combined with an ability to move armies with a speed that Roman generals found bewildering. In 244, Sapor, although beaten a year before at Resaina in northern Mesopotamia, managed to defeat the army of Gordian when it advanced down the Euphrates; in 252, aided by a Roman deserter named Mariades, he fell upon a Roman army and destroyed it (Potter 1990: 267-77, 297-8, 300-3). He followed up this victory with a summer-long tour of destruction throughout Syria. In 260 he outmaneuvered Valerian in the vicinity of Edessa (Potter 1990: 331-7). This victory was followed up by another long raiding expedition.
Although the Sasanian kingdom fell into a period of disarray for several decades after Sapor died (Frye 1984: 303-5), it is plain that the new power was categorically different from the one that had preceded it. Rome now had an enemy that it could not ignore. The Sasanians were capable of taking the initiative in their dealings with the empire, and would often be able to dispose more powerful forces. It was not since the early years of the republic that any Roman state had been confronted with an adversary of such power, and it broke the mould in which standard Roman behaviors in dealing with foreign peoples had been formed. Arab traditions reveal that Ardashir and Sapor both took an interest in the tribes of northern Arabia, seeking to bring
Figures 8.1a-j Sapor and his enemies. One of the most obvious differences between Persia and Rome in the mid-third century was the stability of Sapor’s regime as compared with the situation in the Roman Empire. This plate depicts Sapor and the emperors of the central government who held power between 241 and 272. (a) Sapor I (Gobi); (b) Gordian III (RIC Gordian III n.5); (c) Philip I (RICPhilip 44b); (d) Decius (RICDecius 29c); (e) Trebonianus Gallus (RICGallus 69); (f) Aemilianus (RIC Aemilianus 6); (g) Valerian (RIC Valerian 46); (h) Gallienus (RIC Gallienus 192a); (i) Claudius II (RIC Claudius II n. 32); (j) Aurelian (RIC Aurelian 381). (Figure 8.1a courtesy of CNG; all other coins from the editor’s collection)
Them within the Sasanian orbit (Bowersock 1983: 132). We do not know how significant an innovation this was, but the evidence for Palmyrene trade through the Persian Gulf state of Mesene (usually a part of the Parthian kingdom) suggests that the Palmyrenes had built up a substantial military force of their own to control these tribes, and that this dominance was challenged by the new regime. Likewise, the establishment of a member of the Sasanian royal family (a far more close-knit group, at least in the early period, than the Arsacid clan had been) in Mesene brought that region much more closely under the control of Ctesiphon. There is some reason to think that, in the course of the 250s, after Sapor’s victory and subsequent sack of Antioch, the shift in the balance of power in the desert began to have a very negative impact on Palmyra. Such a shift might explain why the power of Palmyra, invisible at the time of Sapor’s first invasion in 252, became a significant factor during the immediate aftermath of the campaign of 260 (Hartmann 2001: 76-86).
In addition to changing the military and diplomatic balance of power, the Sasanian dynasty had a significant impact on the flow of ideas. Sapor appears to have been something of a proselyte for the wisdom of Zoroaster. It was under Ardashir that an official edition of the ancient Gathas of Zoroaster was assembled, and we know that Sapor actively promoted the cult in the lands that he conquered. It was under Sapor that the career of Kartir, who occupied a preeminent position in the religious structure of the state after Sapor’s death, got its start.
Devoted though they were to the wisdom of Zoroaster, neither Ardashir nor Sapor appear to have been religious bigots. It was in the time of Ardashir that one of the most remarkable religious movements of the third century began. This was the faith founded by the prophet Mani, whose revelation combined various forms of indigenous eastern thought with a peculiar brand of Christianity. Although he was executed as a result of the machinations of Kartir in the reign of Bahram II, Mani had been received by Sapor, and made extensive contacts in the Sasanian court.
Mani traveled widely throughout the Persian Empire, and once visited India, but he does not seem to have visited the territory of Rome himself. His missionaries did, possibly following the trade routes between India and the west. There is a tradition that Zenobia received them at Palmyra, and they seem to have reached Egypt in the course of the 260s (Gardiner and Lieu 1996: 153). They were to have a significant impact during later centuries both on the intellectual life of the Roman world and in central Asia. Another sign of the increasing importance of traditions that emerged in the Persian Empire might also be the peculiar decoration of a late-third - or early fourth-century Mithraeum, found near Apamaea in Syria, which, by way of contrast with Mithraea in the west, is decorated in a distinctively Persian style (Gawlikowsky 2000). Yet another result of the diffusion of ideas from the Persian Empire westward would be an increasing tendency as the third century turned into the fourth to regard such wisdom as dangerous to ‘‘true’’ Roman thought. Diocletian would order the burning of Manichaean books, and Constantine would later attempt to preach the virtues of Christian doctrine to Sapor II (Corcoran 2000: 135-6; T. D. Barnes 1985: 130-2). In the course of the fourth century, with the rise of Christianity within the Roman Empire, the struggle between the two powers would include a definite undercurrent of religious hostility. This need not be seen simply as a result of the exclusivity of Christian doctrine (well matched by that of Zoroastrianism). It may also be seen as a sign that, while the Roman state might not be bothered by views emanating from peoples thought to be weaker, it was less welcoming once those peoples were seen to be its political equals.
World History
