Conclusion

The escalation in conflict on Rome’s eastern frontier, which the Sasanian overthrow of the Parthians heralded, took some time to be reflected in Graeco-Roman literature as a serious problem for the empire. Roman responses to Sasanian attacks on Mesopotamia took place in the same manner as responses to Parthian challenges in the preceding centuries. Along similar lines to the second-century invasions of Trajan, Lucius Verus and Septimius Severus, an invasion into the Persian Empire followed a campaign begun to deal with an immediate territorial threat in the East. Gordian III responded to Persian activity in Mesopotamia in the same way that Severus Alexander had, although his defeat at Meshike and his death ended any prospect of an advance further into Persian territory. In the SKZ we have the Persian version of the invasion of Gordian III, which provides a different account. According to the SKZ the invasion of Gordian III was the beginning of Shapur I’s series of glorious victories over the Romans. It is significant that Oracula Sibyllina XIII, the only contemporary Graeco-Roman text, which was a provincial Syrian one, did not contradict the SKZ on this point. Both Oracula Sibyllina XIII and the SKZ were written soon after the Persian invasions of the 250s by which time Shapur had much to boast about and local Syrians understood the devastating nature of Sasanian attacks. The SKZ was constructed to demonstrate Persian success and Oracula Sibyllina XIII was designed to predict the deliverance of Syria from the Persians. At a distance from this, however, fear of the Persians is less of a feature in the Roman source tradition of the fourth century and later where the emphasis remains on internal weakness as the reason for the defeats in the third century.

The agreement between Philip and Shapur I following the death of Gordian III represented the first concession made by the Romans to the Sasanian Persians. Possible territorial concessions in the agreement are the subject of ongoing debate, but it is difficult to use the SKZ as evidence for this. It is also difficult to use the archaeological evidence to assist in arguments regarding territorial concessions as it is unable to confirm the intricacies of an agreement as proposed in modern scholarship. Ongoing Roman intervention in Armenia was the pretext Shapur promoted as his justification for a war against the Romans, and this saw serious defeats of Roman armies and the capture of dozens of important cities. These were unprecedented events and the first significant attempt to challenge Roman expansion both along and across the Euphrates since Pompey’s establishment of the province of Syria in the middle of the first century BC.

On a close reading of the SKZ and other texts it seems that there were a series of campaigns of differing magnitudes, which together comprised the first Syrian campaign beginning in 252/253. The features of the campaign that Shapur was eager to publicize were the victory over the Romans at Barbalissos and the capture of Antioch. The inscription provides no details other than the capture of cities and their surrounding territories, from which we are able to reconstruct the movements of the invading Persian army in some way. The surviving Graeco-Roman literature provides very little detail of the events of this devastating invasion, but there are some valuable references and allusions.

The impact of the Sasanian invasions on the middle Euphrates and lower Khabur rivers can be surmised due to our knowledge of the Roman garrison at Dura Europos in the first half of the third century. The importance of this city to military and administrative organization on the Euphrates and the Khabur rivers provides a more detailed picture of the likely impact of the invasions of Shapur I than the textual evidence allows. The area over which Dura had an impact militarily was enormous, but the numbers of soldiers at various locations were small. Dura’s garrison probably numbered little more than 3,000 men at any stage in the first half of the third century.248 The files of a component of its garrison, Cohors XX Palmyrenorum, show that many smaller fortifications along the Euphrates in both directions, as well as those on the Khabur, were reliant on soldiers being stationed there from the Dura garrison. Various small fortifications, together with at least two other cohorts on the lower Khabur, demonstrate that there was an obvious Roman military presence on the middle Euphrates and Khabur but that it was too small to provide effective defence in the face of a major invasion. Roman soldiers obviously performed many other duties in the long intervals between conflicts with Persia and were stationed there primarily to perform those duties. There are many examples from the papyri that indicate the importance of the Euphrates and Khabur to agricultural production from the Seleucid to the Roman periods. The regular presence of soldiers for the purposes of law and order and tax collection, together with the presence of the fortifications themselves in this productive area, stamped visible Roman authority on it. The civil documents from Dura indicate the importance of the city as an administrative centre from the Parthian period and the early decades of Roman rule, and this clearly continued in the third century. As an official registry for all types of legal, financial and personal documents it was an important component in the administrative organization of a large area. The invasions, which included Dura’s capture and abandonment in 256/257, clearly had a major impact on those living in the Euphrates and Khabur valleys, and in the longer term the middle Euphrates below the Khabur was abandoned by Rome permanently.