Rome's relations with Persia had worsened drastically since the beginning of the sixth century, culminating in the outright, although limited, confrontations of 502–7 and 527–32.29 The two powers were well matched. The geographical scale of the Sassanian Empire corresponded closely with that of the Roman Empire of the East, although the large expanses of desert country in the center and southeast of Iran probably contributed relatively little to the state's overall resources. The Persian domain as a whole was predominantly a highland one, dominated by the two great chains of the Zagros and Elburz mountains, which came together in the knotted volcanic landscapes of Azerbaijan (Map 11.1). The main reservoir of agricultural wealth was in the flat lands of Mesopotamia and in the middle and lower reaches of the Euphrates and the Tigris rivers. A hydraulic civilization, based on labor-intensive irrigation, made this the Sassanian counterpart to the Nile Valley. Since the region's produce could not easily be exported, it was inevitable that the largest population centers and the imperial capital, Ctesiphon, should be located here. History had shown that the Mesopotamian base of Persian power was vulnerable to attack from the Roman side. The approaches from the north along the two river valleys were accordingly strongly defended by fortresses and fortified cities, which are well documented in the accounts of Julian's invasion of 363 (see pp. 82–3). The northern frontier of the Iranian Empire stretched to the steppes of central Asia, exposing the Sassanians, even more than the Romans, to attacks from the nomadic peoples of the Asiatic steppe. Throughout the fifth century the Huns north of the Caucasus, and the Hephthalites across the huge zone which extended from the Caspian to the Aral Sea, were an unabating threat, and this was the main factor that kept the Sassanians and Romans from going to war with one another in the fifth century. The defenses against the barbarians depended on Persian garrisons in the main trans-Caucasian passes, which were maintained partly with the aid of Roman subsidies, and by elaborate, multi-linear defensive walls, west and especially east of the Caspian. The latter defended one of Persia's wealthiest regions, the horse-breeding grasslands of the Gurgan plain, ancient Hyrcania, the recruiting ground for much of the Sassanian cavalry force.30
Map 11.1 The Roman Empire and the East in late antiquity
Despite its huge land area, geographical diversity and disparate ethnic populations, the Sassanian Empire had been forged into a unity by means which were broadly analogous to those of the Roman Empire. Power was focused on the kings and projected by visual propaganda: imposing buildings, elaborate symbolic reliefs, repeated ceremonials, coinage, and the distribution of prestige gifts, notably silverware decorated with traditional images of royal authority. Sassanian rulership was based on a warrior ethos, and until a serious defeat of the aged Khusro I in 576, the Sassanian kings usually led their forces in person.31 The monarchic system was stable and effective, as is clear from the long reigns of many of the rulers, although there is ample evidence at various periods for challenges to individual kings, either headed by disaffected elements of the landed nobility or as a result of regional insurrection.32 Secular authority was consolidated by a centralized state religion, often misleadingly labeled Zoroastrianism, which was controlled by a cadre of high priests (magi) and based on fire-worship. The importance of this is underlined in the mid-sixth century by Agathias, writing about the originator of the Sassanian dynasty, Ardashir I:
He was a devotee of the magian religion and a practitioner of its mysteries. Consequently the priestly cast of the magi rose to inordinate power and arrogance. It had indeed existed before, and its name was very ancient, but it had never before been elevated to such a position of privilege and immunity…Nowadays…the magi are the object of extreme awe and veneration, all public business being conducted at their discretion and in accordance with their prognostications. In private affairs too they preside over and oversee the proceedings when anyone makes an agreement or conducts a suit, and nothing whatever is held to be lawful and right among the Persians unless it is ratified by a magus. (Agathias 2.26.3, trans. Fowden)
Fire altars were maintained throughout the empire. Eternal fire symbolized the ubiquitous and enduring presence of the supreme Iranian god, Ahura-Mazda, who was depicted in many of the great royal reliefs of the Sassanian kings at the moment of investiture, passing the ring or diadem of power to the new monarch.33
In assessing the military potential of the Sassanians, as with the Romans, a distinction should be made between regionally based garrisons, especially along the northern frontiers, and the mobile armies, with a preponderance of cavalry, which were the main opponents of Rome to the west. The accounts of Roman–Persian warfare in the sixth and early seventh centuries imply that the two sides were closely matched. At full strength the Persian campaigns into Mesopotamia may have brought together field armies of up to 60,000 men.
It was an inevitable consequence of the comparisons that could be made between them, that the Roman and Sassanian empires conceived themselves as a complementary pair. This is implicit in the symbolism of world rulership found in Shapur I's great triumphal relief carved in a cliff beside his new city at Bishapur. At the center of the composition was the enthroned figure of the great king. To his right were the ranks of his own supporters and vassals; to his left were his defeated enemies, and among them the captured standards of Roman legions. But the rows of Romans and Persians were placed on a level with one another, with the implication that Shapur claimed merely to have subordinated his enemies, not humiliated them. In the fourth and fifth centuries, despite the military and political rivalry between the great powers, this imagery was developed and consolidated by generations of diplomacy (see pp. 130–2). In their diplomatic correspondence the respective titles of the rulers were carefully and ostentatiously weighed against each other. Metaphorically, the two empires became the two eyes or two lights of the world, language which acknowledged them as cultural as well as political equals, in contrast to the darkness of uncivilized barbarism which lay beyond their frontiers. The notion was most clearly expressed by Peter the Patrician, Justinian's long-serving master of offices, who had undertaken numerous diplomatic missions to Persia, and who put these words into the mouths of Persian negotiators in 298:
It is apparent to all mankind, that the Roman and Persian empires match each other as though they were two lights, and it is necessary that like eyes they should be adorned by the light from their counterpart and should not treat each other as enemies with the aim of wiping each other out. (Petrus Patricius fr. 13)
The same conception was expressed in a letter sent by Khusro II to the emperor Maurice in 590 (Theophylact 4.11.2).
In the sixth century Persian power increased, above all thanks to the rulership of Justinian's near contemporary, Khusro I (Khusro Anurshivan, “immortal soul”), who ruled from 531 to 579. Procopius presented him as a Sassanian Justinian, “an extraordinary lover of revolutionary innovations” (Bell. Pers. 1.23–1), but the extremely complex middle Persian and Arabic sources indicate that he carried out a comprehensive reorganization of the land and poll tax, at the same time as reforming the structure of the army by creating a more centralized elite cavalry force from the nobility.34
The relationship between Rome and Persia from the mid-sixth to the early seventh centuries was dominated by three major acts of aggression, two from the Sassanian side by Khusro I in 540 and Khusro II in 603, and one, in 573, by Justin II. The “endless peace” of 532 between Rome and Persia lasted only until 539. Procopius placed the responsibility firmly on Khusro I.35 An initial casus belli arose from a dispute between the Saracens under Al-Mundhir, who were linked to the Sassanians, and other bands under Al-Harith (Aretas), Rome's ally, concerning grazing rights along the frontier district of Syria known as the Strata (see p. 369). There was further friction in Armenia among the major landowning families, whose allegiances were split between Rome and Persia. The Persian faction, led by members of the Arsacid family, which was descended from the old pro-Persian Armenian monarchy (cf. Procopius, Buildings 3.1), brought their complaints to Khusro. The speech which Procopius ascribed to them is doubtless an invention, but it rehearsed in detail Persia's grievances with Rome. During the previous war Justinian had imposed Roman taxes on Persarmenia, subjugated the Tzani, turned Lazica into a client state whose king was subject to a Roman magistrate's authority, attached the Bosporan region to Constantinople, made a defensive alliance with the Ethiopians, and attached the Himyarites and the palm groves of that region to the Roman Empire. The conquests in Africa and Italy underlined the extent of the threat that Justinian posed. Now the final straw was his attempt to make further trouble by putting pressure on Al-Mundir, and supporting Hunnic incursions (Procopius, Bell. Pers. 2.3.39–47). This catalogue of charges encompassed the full geographical sweep of the common frontier of the two empires, from the Caucasus to the Horn of Africa. Khusro was swayed by these arguments. After exchanging diplomatic letters with Justinian in the winter of 539/40, Khusro invaded Roman territory in the following spring (Procopius, Bell. Pers. 2.4.13–26).
The Roman defenses were exposed as being hopelessly inadequate to deal with their opponents.36 The war took the form of the Sassanian army attacking an uncoordinated group of city states. Khusro deployed tactics that were arbitrary, willful, and terrifying. Wholesale massacres and the destruction of cities were interspersed with casual and fleeting threats. The cities of Syria, usually under the leadership of their bishops, tried as best they could to defend themselves or to buy off trouble. The city of Sura was captured by a ruse, and most of its population was massacred (Procopius, Bell. Pers. 2.5). Nearby Sergioupolis, modern Resafa, was spared the same fate when Candidus, its bishop, agreed to pay two hundred pounds of gold as a price for ransoming 12,000 captives that Khusro had taken at Sura, and was given two years to find the money. When Khusro returned to collect the debt, he tortured Candidus until he handed over the church treasures of St Sergius, and even then besieged the city until he had to abandon the attempt due to lack of water.37
Justinian's commanders in the field and their pitifully small forces were powerless (Procopius, Bell. Pers. 2.6.3–8). Beroea was captured and most of the small garrison of Roman soldiers deserted to the Persians (Procopius, Bell. Pers. 2.7.14–18). Khusro agreed not to plunder the land around Hierapolis at a price to the city of 2,000 pounds of silver. Justinian's senior representatives had by now reached Antioch, but declined the terms which Khusro was prepared to offer. The city fell to the Persian assault, abandoned by the Roman troops that had been sent to protect it, and these escaped, unhindered by the Persians, to the suburb of Daphne (Procopius, Bell. Pers. 2.8.25–6). Antioch's inhabitants were treated as those of Sura had been. Many were killed, and others were herded back to Persian territory and resettled in a new city near Ctesiphon (Procopius, Bell. Pers. 2.14.1–4). The destruction of Antioch by the Persians, coming only fourteen years after the great earthquake of 526, was burned on the conscience of the Roman world.38Procopius wrote,
I become bewildered as I write of such great suffering, and transmit it to the record for the future, and I am unable to understand why on earth it should be the will of God to exalt on high the fortunes of a man or of a place, and then to cast them down and destroy them for no cause which is apparent to us. For it is not rightful to say that with Him not everything occurs according to reason, even though He himself then experienced seeing Antioch, whose beauty and universal grandeur even now cannot altogether be made invisible, being razed to its foundations at the hands of a most impious man. (Procopius, Bell. Pers. 2.10.4–5, trans. Dewing)
The fate of Antioch was simply irreconcilable with belief in the providence of a righteous God.39
Khusro offered peace terms: an indemnity from the Romans of 5,000 pounds of gold, to be supplemented by an annual payment of 500 pounds. For this the Persians would maintain peace and security, garrison the Caspian Gates themselves, and raise no further complaints about Dara. The Romans protested that they would thus be seen as tributary subjects of Persia, but Khusro insisted that there was a distinction: The Romans would simply be paying the Persians as if they were hired mercenaries, just as they already made annual payments to the Huns and the Saracens, so that these would protect Roman territory from plundering (Procopius, Bell. Pers. 2.10.1–3). The system of securing peace by paying protection money, which had served Constantinople through much of the fifth century, was to continue.
As these conditions were transmitted to Justinian for ratification the Persians continued to turn the screw on the provinces of Syria and Mesopotamia, which were now at their mercy. Khusro undertook a victory parade and fund-raising tour around the remaining major cities of Syria, threatening and plundering at will. From the sea at Seleucia, where he bathed symbolically in the Mediterranean, he passed through Daphne, torching the Church of St Michael, and came to the great city of Apamea, whose inhabitants were spared massacre or deportation by a famous miracle of the Cross.40 Famously, the Persian king ordered charioteers to stage a race in the hippodrome, and supported the Greens. This advertised his victory over Justinian, who had been a long standing backer of the Blues before he became emperor. Chalcis ad Belum and Edessa were spared from being besieged on payment of 2,000 pounds of gold (Procopius, Bell. Pers. 2.12). News now reached Khusro that Justinian had accepted his terms, at which he released the hostages he had taken and offered to sell back the prisoners of war taken in captivity from Antioch. The detailed local sources, which were clearly available to Procopius, indicated that the whole population of Edessa, including the prostitutes and humble peasants, contributed to the fund to buy them back, but were prevented from doing so by the Roman magister militum Bouzes. Khusro himself declined similar payments offered by the people of nearby Carrhae, on the grounds that as unbelievers (moon-worshippers) they should not be buying the freedom of Christians. Evidently the Sassanian king saw the inhabitants of pagan Carrhae as a potentially important fifth column in Roman Mesopotamia. Further payments were extracted from Constantina, but Roman troops commanded by Martinus staged successful resistance when Khusro attempted to besiege and storm Dara. This Persian attempt to take the city was construed by Justinian as a breach of the freshly negotiated agreement with Khusro (Procopius, Bell. Pers. 2.13).
In 541 Belisarius returned from Italy and finally took up his command on the Persian front. This signaled a decision by the belligerent emperor to fight back against the Sassanians at all costs rather than agree the terms that had been offered. The theater of war now extended to Lazica in the north. Justinian's troops and their commanders had alienated the local population, and the Lazi turned to Khusro for help.41 The Sassanians moved virtually unopposed into Lazica and stormed the main stronghold at Petra. John Tzibous, the Roman commander, perished from an arrow shot and many of the Roman troops deserted (Procopius, Bell. Pers. 2.17). This news was brought to Belisarius when he reached the Syrian front and spurred a counterattack on Mesopotamia (Procopius, Bell. Pers. 2.15.14–35, 2.16). However, his forces took only the small stronghold of Sisara (Sisauranon). Their supposed allies, the lightly armed but highly mobile Saracen forces under Al-Harith, made off with the plunder, while Roman troops succumbed to fever in the blistering summer heat, and a third of them had to be invalided out on wagons. The force also returned to protect Roman territory exposed to raiding by the hostile Saracen tribes led by Al-Mundhir (Procopius, Bell. Pers. 2.18–19).
In the spring of 542, Khusro weighed the prospect of making a rapid swoop across the desert via Palmyra to Palestine and Jerusalem. Meanwhile Belisarius opposed him with the combined, but inadequate Roman forces in Syria. At a parley with Khusro's legate, Belisarius attempted to cover his military weakness with a show of strength, a studiedly casual parade of six hundred troops, purposely picked from the full ethnic range – Thracians, Illyrians, Goths, Heruli, Vandals, and Moors – dressed in hunting gear. The Persians withdrew, pausing to take captive the peasant inhabitants of Callinicum. However, it is clear that they had not been deterred by the Romans but by a far more devastating enemy, the plague, from which neither the Persian nor the Roman Empire was spared (Procopius, Bell. Pers. 2.21.23–24).
Fear of the plague restricted campaigning in 543 to the northern highlands east of the Euphrates. The Romans sent large forces on a front which extended from Theodosioupolis (Erzurum) in the north, to Martyropolis in the south. From this broad front they converged eastwards against the city of Dubios (Dvin) in eastern Armenia, close to the old center of Artaxata, eight days journey east of Theodosioupolis. (Procopius, Bell. Pers. 2.25.1–4). The Persian commander Nabedes lured the Roman forces into an ambush and inflicted a major defeat on them, capturing most of their baggage train and weapons (Procopius, Bell. Pers. 2.25.5–35).
In 544 Khusro turned his attention again to Mesopotamia, setting his sights on Edessa, which had defied him in 541 (Procopius, Bell. Pers. 2.12.7–34). According to Procopius, this attack on a major Christian center was to be intended as an attack on the God worshipped by the Christians. The Persians were eventually obliged to withdraw, having extracted a payment of 500 pounds of gold (Procopius, Bell. Pers. 2.26–27). Justinian now sent ambassadors to discuss an armistice, seeking the return of Lazica and a lasting peace. Khusro agreed a five-year truce on these terms, provided that he also received 2,000 pounds of gold and the services of a Roman physician who had previously treated him successfully for an unspecified condition (Procopius, Bell. Pers. 2.28.1–11).
The truce which was established in 545 and renewed in 551 led to a cessation of hostilities on the Mesopotamian frontier. Meanwhile the main theater of war shifted to Persian-occupied Lazica, which had been expressly excluded from the terms of the armistice. Lazica, modern Georgia, was an extensive and fertile enclave at the east end of the Black Sea, providing a sharp environmental contrast to the mountain arena which formed most of the frontier lands between the two empires. Since the 460s its rulers, and probably most of the population, had been Christian. Although it was exposed to strong Persian political influence, most of the Lazi resented Sassanian attempts to rule them (Procopius, Bell. Pers. 2.28.25–26). Lazica became a focus of Roman attention as a result of the Roman thrust in the 520s to Christianize the Black Sea (see pp. 140–1). Major Roman fortifications were built at Petra and at the inland site of Nokalakevi/Archaeopolis. The region also controlled access from the west to the passes through the Caucasus, which were of particular concern to the Sassanians as they sought to defend themselves against the Huns.
Khusro had mixed reasons for his designs on the region. By imposing himself on Lazica he hoped to contain rebellious elements in neighboring Iberia, which was always regarded as part of the Persian Empire, to secure the Caucasus passes against the Huns, and, by gaining access to the Black Sea, to create the possibility of a direct seaborne attack on Constantinople. His ultimate ambition was to remove the pro-Roman king Goubazes, transplant the Lazi elsewhere in his empire, and replace them with more complaisant Persian settlers (Procopius, Bell. Pers. 2.28.18–30, 8.7.12). The focal point of the hostilities was Petra, whose impressive fortifications are still well preserved. The historian Agathias noted that the emperor's determination to secure Lazica was motivated both by loyalty to Rome's friends, and by religion (Agathias 2.18.6). The mostly Christian inhabitants of the region had divided loyalties, but tended on balance to give more encouragement to Rome than to Persia. For several years control was divided, with Roman forces dominating north of the river Phasis, while the Persians held southern Lazica around Petra. In 551 the latter were driven from Petra by the Roman general Bessas, and forced back into the hinterland and the approaches to Iberia, thus relinquishing their foothold on the Black Sea coast. The conflict now shifted to the interior of the country, and continued until 557. Eventually the Sassanians gave up the struggle, defeated in the last analysis by logistic difficulties in sustaining a war so far from the centers of their empire (Agathias 4.30.7). Lazica was definitively ceded to Rome in the treaty of 562.42
The peace agreement between Rome and Persia, which was finally agreed by plenipotentiaries of the two rulers at a neutral location on the frontier near Dara in 562, is the fullest treaty document to have survived from the ancient world. The contents were checked word for word, guaranteed by the seals of a team of twelve interpreters, and recorded with equal scrupulousness by the historian Menander (fr. 6). It is not impossible that he personally had been one of the translators of the document. The treaty was to last for fifty years. Clauses dealt with the Caucasus passes, the role of the Arab tribes, the activities of Roman and Persian merchants and the points at which they could cross the frontier, the protection and privileges of official ambassadors and couriers, the return of refugees and fugitives to their state of origin, and the settling of civil disputes that arose between Romans and Persians. The recurring feud over Dara was put to rest by the Persians acknowledging that the Romans had a right to retain the fortress, provided that its garrison was no larger than appropriate to a city, and that it was not used as the headquarters of the Roman commander of Oriens. An elaborate article of the treaty set up a system of local judges, with channels of appeal to higher authorities, to deal with complaints of cities damaged by local cross-border feuding.43
The realpolitik was as important as the formal wording of the treaty. The atmosphere in which agreement was reached was tense and hostile. Justinian's magister officiorum, Peter the Patrician, delivered a speech in which he expressly warned the Persians to behave modestly in the presence of the Romans and not to boast of their achievement in sacking Antioch. The Persian response was a calculated insult. Khusro thought nothing of so commonplace an event as the capture of Antioch; leveling a Roman city was all in a day's work for Persian forces. The main territorial advantage for the Romans was to confirm their sovereignty in Lazica. The fact was not mentioned in the treaty. Another condition favorable to Rome was an agreement, not included in the formal treaty, that Christians in the Sassanian Empire should be allowed freedom of worship and to build churches, and not compelled to follow the religion of the magi, although they were not to proselytize. Nestorian Christianity had made significant headway and claimed converts at high levels of society (see pp. 313–4).
However, these gains came at a price and at a cost to Roman prestige. All the sixth-century agreements between Rome and Persia involved payments to the latter, which were a source of deep controversy. In 532 Justinian had secured the “eternal peace” with a single payment of 11,000 gold pounds, which was understood as Rome's contribution to the military costs of securing the Caucasus frontier (Procopius, Bell. Pers. 1.22.3). The five-year truce of 545 was obtained on payment of a further 2,000 gold pounds (Bell. Pers. 2.28.10). In 551 the cost of renewal was only fixed after protracted negotiation. The Persians demanded 2,000 pounds for the coming five years and 600 for the previous eighteen months since the beginning of 550, when payments had been interrupted. The emperor Justinian initially proposed paying 400 pounds annually, to ensure that the Persians adhered to the conditions of the truce, but then agreed to full payment for five years in advance, to avoid the appearance that the Romans were now annual tributaries of the Persian Empire. Precisely these matters were at issue in 562. The annual figure was set at 30,000 gold coins (nomismata), which historians of the seventh and eighth centuries judged to have been worth 500 gold pounds. However, at the usual equivalence of 72 nomismata to a gold pound, the cost per year would have been 416 pounds, virtually the same as in the previous agreements.44 There was to be an immediate payment covering the first seven years, followed by one for three years, and annual payments thereafter. Theophylact, but not the contemporary Menander, interpreted the payments as covering the cost of the Caucasus garrisons (3.9.11). It is evident that their significance and purpose could be read in different ways. For the Persians, and for internal critics of Justinian, they would naturally be understood as a form of tribute. The Roman regime presented them as a cost-effective subsidy to a foreign nation which was undertaking defense duties on its behalf, although the fact that the Caucasus passes were largely irrelevant to Roman defenses made it increasingly difficult to sustain this argument.
The atmosphere in which the treaty of 562 had been concluded indicates that relations between Rome and Persia in the later sixth century were sour. This is confirmed on the Roman side by the hostile tone to be found in the authors of the period. Procopius provided a damning assessment of Khusro I, understandable from the viewpoint of a writer who had witnessed at first hand his lack of scruple and the conduct of his armies during the invasions of Syria and the sack of Antioch (Procopius, Bell. Pers. 2.9.8–18). Agathias painted an even more hostile picture of the Persians, as barbaric, perverse, and cruel.45 This was to be expected at a period when the political outlook of the two great powers was polarized between the political and religious stance of two domineering rulers, Justinian and Khusro I, which sharpened the geopolitical conflict.
In 569 Justin II, Justinian's successor, agreed to the second, three-year installment of payments to the Sassanians, but the demand for annual payments from 572 was one of the casus belli which led to the outbreak of another Roman–Persian war. The Romans also found other reasons for complaint. The largely Christian population of eastern Armenia (Persarmenia) allegedly wished to be part of the Roman Empire (John of Ephesus, Ecclesiastical History 2.32), and assassinated their Persian governor (Evagrius 5.7); the Sassanians were interfering in the affairs of the Himyarites in the Yemen, claimed as part of the Roman protectorate since the 530s. Meanwhile Justin's agents were plotting to coordinate hostilities with the emergent power of the western Turks, who had replaced the Hephthalite Huns as a major threat to Persia from the steppes. A Persian embassy to Constantinople, led by an Armenian Christian, responded unprovocatively, merely requiring continuation of the promised annual subsidy, but it was repudiated by an emperor bent on war (Menander fr. 16). Justin sent his nephew, the patricius Marcian, with 3,000 inadequately equipped troops drawn from the local frontier garrisons, to begin a war in Arzanene, the Persian province north of the Tur Abdin and east of Martyropolis (Theophylact 3.10.1–3).46 The attack provoked a crushing response from the Sassanians in 573. Khusro himself overwhelmed the Roman forces near Nisibis and after a six-month siege captured Dara. His general Adarmahan crossed the Euphrates at Circesium and reached the Orontes Valley, the heart of Roman Syria, ravaging the suburbs of Antioch and putting Apamea to the torch (Evagrius 5.9–10; John of Ephesus 6.5–6; Theophylact 3.10.4–11.4). The loss of Dara is said to have driven Justin II mad. His wife Sophia took a prominent role in agreeing terms with Khusro in spring 574, involving further Roman payments which secured peace in Mesopotamia but which left the Armenian question unresolved (Evagrius 5.11–12; Menander fr. 18, 37–8). Another consequence of the debacle was the adoption of Tiberius II to succeed Justin II, creating a virtual regency until the latter's death in 578 (Evagrius 5.13).
The uneasy truce was prolonged until 576 (Theophylact 3.12.10; Menander fr. 39–40, 50). Rome used the respite to rebuild military strength and discipline (Theophylact 3.12.7; Evagrius 5.14), and these were formative years for the future emperor Maurice, himself an author of a work on military tactics and one of Rome's great warrior rulers. In 576 the adversaries launched attacks on one another, the Romans attacking Armenia from the direction of Amida in Mesopotamia, while Khusro led his forces across the Euphrates against Caesarea in Cappadocia. On the return march he sacked Melitene, but his army was ambushed as it withdrew east across the river (Menander fr. 18.6; John of Ephesus 6.8–9; Evagrius 5.14), with the loss of men, booty, and the king's personal fire altar. Roman historians report that from this moment a law was introduced that Persian kings should no longer lead military expeditions. Khusro's personal prestige was seriously damaged by the debacle and he was threatened by mutinies,47 while the events of these years show that properly equipped and trained Roman forces were more than a match for the Sassanians in the frontier areas. The initiative passed now to the rejuvenated Roman forces. An army invaded Azerbaijan, through the territory of Persarmenia and Iberia, where it found significant support from the Christian populations, and overwintered deep in Sassanian territory in 576/7 (Theophylact 3.15.1–2; John of Ephesus 6.10). This strategy was replicated exactly half a century later in the devastating counteroffensive staged by Heraclius against Khusro II (see p. 453). Fierce fighting continued in spring 578 with a Sassanian thrust into Mesopotamia, followed by a Roman counterattack against Arzanene and beyond the Tigris as far as Singara, led by Maurice (Evagrius 5.19; Theophylact 3.15.11–16.2; John of Ephesus 6.15).
Justin II died in October 578, followed by Khusro I in the following spring, during negotiations which aimed to return Dara to Roman control and sovereignty over Persarmenia and Iberia to the Sassanians. Khusro's successor Hormizd, however, broke off the diplomatic exchanges and initiated a further period of warfare on the Mesopotamian front. In 580 and 581 Maurice led attacks into Media and Mesopotamia respectively, in the second year at first aided but then betrayed by the Ghassanid leader Al-Mundhir. The following year he defeated a Sassanian force, which had counterattacked near Constantina in Mesopotamia, before returning to Constantinople where he became emperor in succession to Tiberius, who died in August 582 (Theophylact 3.17.5–18.3).
During the early years of Maurice's reign matters along the eastern frontier remained in the balance. Maurice sent his treacherous Arab allies, Al-Mundhir and his son Numan, into exile (Evagrius 6.2), while John the Thracian and Philippicus led Roman campaigns in Arzanene and the territory of Nisibis. Priscus replaced Philippicus late in 587, at a moment when financial pressures forced the emperor to reduce military pay. This provoked a serious mutiny, which erupted at Easter 588 in Mesopotamia. The troops elected Germanus, the military commander in Phoenice Libanensis, to supplant Priscus, and the emperor himself re-appointed Philippicus to the command in Mesopotamia. Germanus himself, aided by further promises of imperial money, calmed the mutineers and led a successful campaign against the Persians, who had taken advantage of the confusion to attack Constantina. Germanus won a significant victory at Martyropolis, and the booty taken from the Sassanian army went some way to meeting the soldiers demands (Theophylact 3.1.1–4.6; Evagrius 6.4–7, 9). Gregory, the bishop of Antioch, played a leading role in conciliating the army with its imperial commander, Philippicus. It appears from Evagrius' virtually contemporary account of these actions that Gregory was effectively the secular as well as the ecclesiastical leader of Antioch, and responsible among other things for recruitment and the provision of logistical supplies to the army (Evagrius 6.11–13).48 However, 589 saw a further setback when Martyropolis was betrayed to the Persians. Philippicus, who was unable to recover the city, was again replaced by Comentiolus, and hostilities continued in Arzanene between Roman forces, who had seized the stronghold of Akbas, and the Persians, who maintained their bridgehead in Roman territory at Martyropolis (Evagrius 6.14–15; Theophylact 3.5.11–15).
Decisive developments came from a different quarter. The catalyst was the appearance of a major new force in the steppes east of the Caspian, the western Turkic tribes led by their Chagan.49 The Turks demanded huge sums of protection money from the Sassanians to keep the peace along the northern frontier:
The Turkish realm, then, had been made very rich by the Persians, and this particular nation had turned to great extravagance; for they hammered out gold couches, tables, goblets, thrones, pedestals, horse-trappings, suits of armour and everything which has been devised by the inebriation of wealth. Subsequently when the Turks broke the treaty and demanded that they be given more than the customary money and that there should be a very heavy supplement, the Persians, intolerant of the burden of the imposed tribute, elected to make war. (Theophylact 3.6.11–12, trans. Whitby and Whitby)
The successful Sassanian reprisals were led by Bahram-i Chubin, a member of one of the great families that rivaled the Sassanians, and commander of the regions of Armenia and Azerbaijan. Bahram then proceeded to attack the Caucasian kingdom of Suania, which was a perpetual source of dispute between Rome and Persia in the western Caucasus.50 The Roman response was to send a force to Lazica, which advanced east into Albania and defeated Bahram's forces at a battle on the river Araxes (Theophylact 3.6.15–7.19). Bahram then defied the attempt of the Sassanian king Hormizd IV to dismiss him from his command, and led his mutinous forces as far as the river Zab (Theophylact 3.8.1–3, 10–12). This threat caused widespread further defections among Hormizd's followers, and the king was overthrown in a palace coup at Ctesiphon, were he was briefly succeeded by his son Khusro II (Theophylact 4.1.1–3.12). Bahram's army now moved southwards towards Ctesiphon and defeated Khusro, who was left with no option but to flee westward with his harem and a small entourage of followers to seek Roman protection. He was escorted from the frontier city of Circesium to Hierapolis where Comentiolus, commanding the Roman forces of the east, received him in March 590. As Bahram seized royal power in Persia, Khusro sent a delegation with a proposition for the emperor Maurice. If the Romans restored him to his throne, he would give back Martyropolis, Dara, and control over Armenia (Theophylact 4.13.24). The Armenian chronicle attributed to Sebeos preserves a similar narrative of these events but defines more precisely Khusro's territorial offer to Maurice: the region around Nisibis, control of Armenia as far as Mount Ararat, the city of Dvin and Lake Van, and territory in Georgia as far as Tiflis (Armenian Chronicle Attributed to Sebeos 76, 84). Rejecting the advice that Rome's interests were best served by leaving the Persian rivals to fight between themselves, Maurice decided to accept Khusro's proposal. This initiated an energetic and complicated campaign, much of it in the region around Lake Urmia in Azerbaijan. Bahram's forces were eventually worsted at a battle near Ganzak, and the usurper fled to the east, seeking sanctuary among the Turks, but was murdered soon afterwards. These events marked a high point in Rome's struggle along the eastern frontier. Roman garrisons not only reclaimed Dara and Martyropolis, but also took charge of much of Persarmenia.51
The events of 591 also sealed the relationship between the two great powers. Maurice's decision to support Khusro's legitimate claims against the usurper Bahram acknowledged the argument, expressed in Khusro's pleas for help, that the two empires gained more than they lost from having a stable counterpart on their frontier. It also showed a confidence in Roman strength, which was justified by the strategic gains of the campaigns of 590–1. What was not foreseen was that, less than a dozen years later, the favor shown to Khusro would be precisely reciprocated, as Maurice was in turn overthrown by the usurper Phocas, and a man who claimed to be his son, Theodosius, fled to safety under the protection of Khusro.