A chapter dealing with Iranian feudalism in a distinguished series dedicated to The rise and fall of the Roman world bears the title ‘Iran, Rome’s greatest enemy.1 This title is more than merely a justification for the inclusion of a chapter on Iran in a work devoted to the history of the East Roman empire. It also reflects a host of fears and prejudices fostered for long centuries in the Roman world, since the trauma of Crassus’ defeat by the Parthians at Carrhae. Not even extended periods of decline and internal disarray within the Parthian monarchy, during which it was repeatedly invaded by the Roman army, could dispel the myth of the uncompromising threat posed by Iran to the Roman order. The replacement of the Parthian Arsacid dynasty by a vigorous new one, based in Fars, namely the Sasanian dynasty, at a time when the Roman empire itself was facing one of its severest crises, only aggravated its inhabitants’ deeply rooted fear of Iran. Ancient writers in the Roman oikoumen¯e passed on this attitude to modern western scholars.2 It is the Sasanian bogeyman which has left a deep imprint in modern historiography. The Sasanian state is widely regarded as a much more centralised and effective political entity than its Parthian counterpart, with a far better army. The great pretensions and aspirations of its monarchs are believed to have been fed by the fervour of religious fanaticism, inspired by the Zoroastrian priesthood, which is commonly depicted as a wellorganised state church. No wonder that such a state posed the gravest threat to its greatest rival – the other great power of late antiquity.3 Each of these accepted beliefs raises a multitude of problems, and a fundamental revision is called for. Only a few of the more salient points can be dealt with here. The Sasanian empire embraced two distinct geographical areas, the very fertile lowlands of Mesopotamia and the Iranian uplands, which were separated from each other by the mighty Zagros chain stretching from the Kurdistan highlands to the fringes of the Persian Gulf in the south.4 Mesopotamia, where a complex irrigation system permitted dense settlement, was the economic heart of the Persian realm. Its rich agriculture generated the largest part of the Sasanian state’s tax revenues and supported a network of major cities: Ctesiphon, the capital; Veh Ardashir, on the west bank of the Tigris opposite Ctesiphon, which was founded by the first Sasanian monarch; Perozshapur on the Euphrates, which commemorated the site of Shapur I’s victory over Gordian and exploited the large number of Roman captives secured then; and Veh Antiok Khusrau, which was a similar foundation by Khusro I to celebrate his capture of Antiochon- the-Orontes and to provide a home for the captives and booty from his successful 540 campaign (see above, p. 120). By contrast, the Iranian plateau was sparsely settled, with its main centres of habitation clustered around the sources of water emerging from the Zagros. Rainfall on the plateau is low and beyond the rivers and qanats (underground water channels) lies desert: the Gedrosian to the south-east, where much of Alexander’s army perished in 324 bc, and to the north the salt desert of the Great Kavir. On the fringes of the Sasanian world were areas of considerable military importance. In the north-west, Iran competed for influence with Rome among the nobilities of Armenia, Lazica, Iberia and Albania, and attempted to control movements across the Caucasian passes. In the wide expanses of Transoxiana, Iran confronted its traditional enemies: the succession of nomadic confederations of the Central Asian steppes. These included the Hephthalites or White Huns, who dominated the frontier in the fourth and fifth centuries; and the Turks, who cooperated with Khusro I in the elimination of their mutual enemy, the Hephthalites, in the 550s, but then rapidly emerged as a much more powerful threat during the rest of the sixth century. The vast barrier of the Zagros restricted communications to a limited number of major passes, so that the structural backbone of the empire was simple: from the economic and political heartland of lower Mesopotamia, routes up the Tigris led to the area of conflict with Rome in the north and north-west; while the road to the east crossed the Zagros intoMedia and then continued along the southern flanks of the Elburz range, another major defining mountain range, towards Khorasan and the frontier. The Sasanian heartland was located in Fars, the relatively fertile region at the south-western end of the Iranian plateau, where the family combined positions of religious authority (the chief priesthood of the temple of Anahita at Istakhr) and secular power (governorship of Darabjird). After two decades in which a strong local power base was transformed into authority over the Iranian plateau, Ardashir descended to theMesopotamian lowlands, overthrew the Arsacid monarch and was crowned ‘king of kings’ at Ctesiphon in 226. Military success, and in particular conflict with Rome, was an important mechanism for demonstrating the legitimacy of the new regime. The initial thrusts of the two first Sasanian monarchs, Ardashir I (224–40) and Shapur I (240–70), against the Roman east turned out, in the long run, to be little more than a series of wars of plunder: the Romans were defeated three times in the field, with Emperor Valerian being captured at Edessa in 260; the great cities of Nisibis, Carrhae and Antioch were sacked; and ravaging extended into Cappadocia and Cilicia as well as Syria – but there were no permanent gains.5 Under their immediate successors, the initiative seems to have passed momentarily to the Romans. The conflicts between the two empires at that time brought the problem of Armenia to the fore, and this was to be a major bone of contention for most of the following century (see below, pp. 156–7). The attempt of Shah Narseh (293–302) to regain the upper hand ended in humiliating defeat by the Romans in 297, followed by a no less humiliating treaty. The tide was partly reversed during Shapur II’s long reign (309–79). The wars fought between the two powers at the time were largely over contested frontier lands – first and foremost Armenia and northern Mesopotamia. Stability began to emerge after Julian’s invasion in 363 permitted the Persians to regain Nisibis and other territories in upper Mesopotamia, and this was reinforced by the treaty between Shapur III (383–8) and Theodosius I in 384, which arranged the division of Armenia.6 This ushered in a long period of relative quiet in relations between the empire and Persia, apart from two brief conflicts in 421–2 and 440–1. On the first occasion, the dispute was caused by the Roman reception of Christian fugitives, especially from the Arab tribes allied to Persia. Yazdgard I (399–420) had been favourably disposed towards Christians and other minority religious groups within his kingdom, but energetic Christian missionary activity seems eventually to have forced him to permit persecution; an Arab chief, Aspabad, was instructed to prevent the flight of Christian converts to the Romans, but he proceeded to join the exodus, converted and, now renamed Peter, became bishop for the wandering tribal groups in the desert.7 Persian demands for subsidies towards the cost of defending the Caspian passes (the so-called Gates) caused the second conflict, when Yazdgard II (438–57) attempted to exploit Theodosius’ concern over the Vandal capture of Carthage. On each occasion Roman armies checked Persian attacks and peace was rapidly restored, with renewed treaties that contained clauses to regulate the alleged origins of the war.8 A plausible explanation for the change from persistent warfare in the third and fourth centuries to peaceful relations in the fifth is provided by the other external problems which faced successive rulers. Developments in the west and the Balkans, as well as internal problems in Isauria, commanded the attention of the emperor at Constantinople, while Sasanian shahs had to contend with the equally serious threat posed by the Hephthalites on their north-east frontier. This Sasanian problem is not regularly reported in our sources. The succession ofGreek classicising historians from Priscus of Panium through to Theophylact Simocatta narrate diplomacy and warfare that involved Romans and Sasanians, but seldom extend their horizons further east.9 Sasanian sources are mostly preserved for us through compilations from the Islamic period, of which the most important are the Ta’rikh of al-Tabari in Arabic and the Shahnama (Book of kings) of Firdausi in New Persian. Both date from the tenth century and depend on lost Iranian sources, in which anecdotal material had substantially ousted reliable information, so that the resulting narratives are dominated by charming and exotic stories. Though al-Tabari attempted to cut his way through the more sensational of his source materials and to produce a sober historical narrative, he still incorporated two parallel versions of Sasanian history: it is not safe to trust his information uncritically.10 Furthermore, these Iranian sources are more informative for the royal court and internal affairs and, like their Roman counterparts, are silent about a difficult frontier relationship in which the Persians were often at a disadvantage. Only for the reign of Peroz (459–84) is there substantial information about Perso- Hephthalite relations, partly because Peroz was defeated in 464–5 when the Roman ambassador Eusebius was accompanying the royal army, and partly because two decades later Peroz perished with much of his army in a catastrophic attempt to reverse the previous humiliation.11 The death of Peroz was followed by a period of dynastic weakness in Iran. Peroz’s brother Valash ruled for four years (484–8) before being overthrown by Peroz’s son Kavad I (488–96), who relied on Hephthalite support. Kavad, however, was in turn ousted by the nobility and replaced by his brother Zamaspes (Jamasp); but he was returned to power (498–531) with Hephthalite assistance, after marrying their ruler’s daughter. Kavad’s reign witnessed the rise of the Mazdakite ‘movement’ (see p. 149 below), which advocated communal rights over property, and perhaps also women. It appears to have received some support fromthe shah, and can be interpreted as an attempt to undermine the entrenched power of the hereditary aristocracy. An indirect consequence of Kavad’s dynastic problems was resurgence of warfare with Rome: Kavad undoubtedly needed money to repay the Hephthalites and to enhance his position as supreme patron within Persia, and this led him to ask the Romans for contributions towards the costs of defending the Caspian Gates. Anastasius’ refusal provided a pretext for war (502–5), and although Kavad’s first campaign secured considerable prestige and booty – with the capture of both Theodosioupolis and Amida – the Roman generals gradually stabilised matters after that.12 Sixth-century Romano-Persian relations are characterised by two opposing tendencies: a recollection of the relatively harmonious fifth century, when elaborate diplomatic practices for managing relations had emerged; and international rivalry, caused both byweakness in the Persian shah’s position and by mutual suspicion of each other’s intentions. In 527, towards the end of Kavad’s reign, war broke out again (see above, p. 119). Tension had risen as the empires competed for the allegiance of the principalities around the Caucasus, where acceptance of Christianity by local rulers threatened to weaken loyalties to Persia. However, the flashpoint came when Justin I (518–27) refused to cooperate with Kavad’s plans to ensure the succession of his third son, Khusro. Although the Persians took the offensive, a series of invasions failed to capture any major Roman city, and two pitched battles – at Dara in 530 and at Callinicum in the following year – resulted in a victory apiece. Hostilities were concluded with the ‘perpetual peace’ of 532, when the new Persian shah, Khusro I (531–79) accepted a lump sum of 11,000 pounds of gold in lieu of regular contributions for the defence of the Caucasus.13 Peace did not last. Justinian (527–65) exploited the quiet on his eastern frontier to launch the reconquest of Africa and Italy, but his startling victories were brought to Khusro’s attention; jealousy fuelled suspicions about Justinian’s long-term intentions, and Khusro exploited a dispute between client Arab tribes to attack in 540. After spectacular Persian successes in this first campaign, the Romans organised their defences and a truce confined fighting to Lazica after 545. However, their Arab allies went on fighting (see below, p. 188). This ended with a decisive victory for the Ghassanid allies of Byzantium in 554 near Chalkis, when the Lakhmid ruler al-Mundhir III – scourge of imperial provinces for the previous half-century – was killed. Peace finally came in 562 with an agreement that was intended to last for fifty years; the detailed terms illustrate the range of disputed issues that could provoke conflict, and are preserved in an important Fragmentum of Menander the Guardsman.14 Peace lasted for a decade, but on this occasion the Byzantines were the aggressors: Justin II (565–78) objected to paying for peace (at the rate of 30,000 solidi per year) and believed that he could count on the support of the Turkish confederation in Central Asia, which had replaced theHephthalites as Persia’s north-eastern neighbours, to crush their common enemy. Two decades of fighting ended when Khusro I’s son and successor, Hormizd IV (579–90), was overthrown in a palace coup; Hormizd’s son, Khusro II (590, 591–628), was almost immediately challenged by Bahram Chobin, who had gained great glory from defeating the Turks and was the first non-Sasanian to seize the throne (590–1). Khusro sought assistance from Emperor Maurice (582–602), was reinstated by a Roman army in 591, and peace was again arranged.15 The final conflict of the two great rivals of the ancient world broke out in 602, when Khusro took advantage of the murder of his benefactor Maurice and the arrival in Persia of Maurice’s eldest son Theodosius (or at least a plausible impersonator); Khusro could shed the image of imperial client, present himself as the supporter of international ties of gratitude and friendship, and obtain significant booty and military glory into the bargain. For twenty-five years the conflict ranged across the entire Middle East, from Chalcedon on the Bosporus to Gandzak on the Iranian plateau, until a daring counter-offensive byHeraclius (610–41) prompted the Persian nobility to overthrow Khusro in 628.16 Once more peace was restored, but the defeated Sasanian dynasty lapsed into a rapid turnover of rulers (eight within five years, including, for forty days, the Christian and non- Sasanian Shahrvaraz). The last Sasanian ruler Yazdgard III (633–51) had only just ascended the throne when he had to confront Islamic attacks; the diminution of royal prestige and the weakness of his armies after a quarter of a century of unsuccessful warfare against Byzantium made Persia particularly vulnerable, and Yazdgard was forced to flee to the north-east, where he was eventually killed. Wars and animosity loom large in the record of the relations between Byzantium and Persia, both of which laid claim to universal ascendancy. The imprint they have left on the Byzantine sources tends to obscure the fact that both sides could also exploit a rhetoric of peace and co-operative relations. The Sasanians, who had to contend with a succession of nomadic and semi-nomadic powers along their extensive frontiers, tried to impress on the Byzantines that they were defending these frontiers for their mutual benefit. This claim justified repeated demands for diplomatic subsidies, but Sasanian internal propaganda depicted these as tribute, which aggravated imperial resistance to paying up:17 international prestige was one of the factors that individual Sasanian monarchs used in order to balance the divergent constituencies within their realm and preserve their own supreme position.