The sixth and seventh centuries, a far stronger reaction to the Avars, Persia, and the Arabs?
The Northern frontier, less of a tribal threat to the Balkans?
The survival of the Western Empire would also have had major effects on the East, which would have had an ally able to send troops in major crises but also a strategic bonus in the upper and middle Danube area. It is possible that the survival of a militarily powerful West through the third and fourth centuries, and perhaps its preservation in the fifth, would have involved a scenario where the Empire held onto or regained Dacia. Apparently evacuated at a time of military crisis in the mid-third century, probably by Gallienus or Aurelian, it might have been preserved as a province had the Empire’s rulers had the will to follow through Marcus Aurelius’ occupation of the Czech lands to the Carpathians in the 180s. Due to lack of firm evidence we cannot say for definite that Marcus had a grand plan of strategy in mind to advance the frontier permanently to the Carpathians, but the discovery of Roman military structures in Bohemia would indicate that a long-term occupation was planned. Lacking a determined resistance from the occupied tribes with outside assistance, the factor which led to the similar advances in Scotland in the 80s and 140s and in Iraq in 114–17 being aborted, there would have been no logical reason for a later Emperor to withdraw in the later second or third centuries.
Thus Rome would have been been defending the Carpathians not the Danube as the frontier against the German tribes through the third century; a limited number of mountain passes and gaps in the Carpathian ridges were easier to defend than a river which was crossable for all its length and needed more troops. This more viable frontier would then have been defendable through the third century, barring major defeats like that of Decius by Kniva’s Goths in 251, even with the Empire’s troop numbers reduced due to the serious outbreak of plague in the early 250s.
Alternatively, Dacia might have been abandoned due to reduced troop levels and the number of attacks from neighbouring tribes, if not in the third century, then under pressure from the Goths as they retreated from the expanding Hunnic empire on the steppes around 376. Roman-held Dacia would then have been an obvious destination for their refugees rather than the south bank of the Danube as in real life. Dacia might have been lost to the Huns themselves in the 430s, or fallen under the weight of attacks by tribal refugees from Attila at a time when the Western Empire could not manage a military response, maybe after the death of Constantius III in 421, in the succession crisis before Galla Placidia secured the throne for her son Valentinian III in 425. In this scenario of a surviving Western Empire, the Rhine would not have been crossed by a permanent Germanic presence in 406, and thus armed bands of warriors from 406 and refugees from the 430s–440s would not have been settling in Gaul, Spain, and Africa. The pressure of westward tribal movements on Dacia and any Roman territories in Bohemia would have been acute, leading to the same sort of demands for admission that the refugee Goths made on the lower Danube in 376. Refusing them admission to the Empire would have run the risk of defiance, armed confrontation, and a Roman defeat such as the Goths carried out in 376–8. Constantius III, who handled the Gothic problem in Spain and Gaul successfully in 411–18 and allowed them a vassal kingdom, and Aetius had the military and diplomatic skill to handle such a Romano-German crisis successfully. Valentinian III, Aetius’ jealous sovereign who assassinated him in 454 and precipitated the West’s fatal collapse, did not.
Even if Dacia and/or the Czech lands had been lost to the German tribes in the early fifth century, this might not have been permanent. Had the West retained a strong comitatus and control of enough provinces to fund it, its commanders had a military edge over disunited invaders. Once Attila’s empire collapsed, there was a potential window of opportunity for reoccupation, or at least securing a peace with tribal leaders on terms favourable to Roman interests. Following precedent, the Empire was likeliest to require some sort of federate vassal status from the local tribal kings, the terms which Theodosius had reached with the Goths still holding out in Thrace in 381, and which kept their commanders under technical Roman command until Alaric’s revolt in 395. Dacia and perhaps the Czech lands could have been reoccupied by Aetius and his armies of Romans and German allies on the death of Attila in 453, or at least secured by Aetius for a group of allied tribes who had won independence from the Huns in the revolt that the latter’s subjects mounted in 454.
In order to secure Roman control of Dacia and the other lands threatening the Eastern Empire’s North-West frontier, source of the major Avar threat frothe 560s, the two Empires would have had to construct a system of alliances with local tribal leaders in the power vacuum after Attila’s empire collapsed. The history of the area after the anti-Hunnic revolt of 454 is obscure, but it would appear that the Huns under Attila’s sons managed to hold onto a domain based around the Ukraine plains and that nomadic peoples from this Western part of the steppes were a continuing threat to the Empire. In the 490s Anastasius found it necessary to construct a massive wall across the Thracian isthmus, about thirty miles west of Constantinople, against repeated raiding from across the Danube.1
Indeed, this threat revived in the 540s and 550s with massive raids on the Balkans by the Kutrigur Bulgars, starting with a two pronged raid into Greece, as far as Thermopylae, and Thrace, as far as the Long Wall of Anastasius, in 540 and culminating in a massive three pronged attack on Thessaly, the Chersonese around Gallipoli, and Thrace, breaching the Long Wall, by Khan Zebergan in 559. The Empire had probably lost immense numbers of current and future soldiers, and farmers, supplying their food, and taxpayers to fund them, in the plague of 542, when Procopius estimated that half the capital’s population died, and its armies were tied down in Italy, Spain, North Africa, and Armenia.
The extra threat to the Balkans from 540 strained its capacities to the limit, and during the 559 attacks the Emperor had to call Belisarius out of retirement and send him to tackle the invaders in Thrace with a hastily raised force of around 500 bucellarii (bodyguards), its size a testimony to the lack of troops available. Luckily, his reputation among the steppe nomads was such that after his initial victories in minor clashes they retreated.2 But the extra dimension of a new nomad threat to the Balkans and the lack of troops to meet it meant that much ravaging went unchecked, undermining the prosperity, and ability to supply soldiers, food, and taxes, of the Balkans. Had the Western Empire still been in existence through the fifth and into the sixth centuries, with or without Dacia, the Kutrigur menace would have been unchanged, the raiders came from the steppes via the lowland corridor of Wallachia, and would still have crossed the lower Danube. Justinian might still have sent his armies to reconquer a schismatic, probably Arian-led Western Empire or intervened in a civil war, and so been unable to protect the Balkan heartland from which he himself came. But if he had not been fighting in the West and had turned his formidable energies on Persia, which the East had been fighting in the late 520s before the opportunity to regain the West arose, he should have had more men available despite the plague and so put up a greater resistance to the raiding from 540.
The second major threat from the steppes in the mid-sixth century, the Avars, arrived in the Ukrainian region some time in the 560s. Their epic move west from central Asia developed as a result of factors out of the Empire’s control, as their first steppe empire was broken up in 552 by a revolt by their Turkish vassals and they had to flee their homeland.3 Ultimately, this tribal revolt had the consequence of destroying the Roman Empire nine hundred years later, the rise to independent political action of the Turkic peoples touched off the migrations that led the Seljuks to Manzikert in 1071 and the Ottomans to Constantinople in 1453. With or without a victorious Western Empire, preserved by Theodosius I, Stilicho, Constantius III, and Aetius from Germans and Huns, occupying Dacia and overaweing the German tribes, the Avars would still have arrived on the steppes facing the Danube. Their threat to the East would have duly developed, with a repeat of fifth century Hunnic history as the incumbent local tribal kingdom facing the Roman Illyrian and middle Danube zone (the Gepids) was destroyed (567) and the threatened Lombards moved West towards Italy. Justinian and, sporadically, Justin II paid off the Avars with subsidies, as Theodosius II had done the Huns in the 440s, but ultimately the price of blackmail rose, 80,000 nomismata per annum as of 574, and the Avars turned on the Empire, probably assisted by the threat of a Roman-Turkish alliance against them.4 In 579 they attacked Sirmium, key to the middle Danube, while the Lombards who had fled ahead of them were invading Italy from 568 and destroying what remained of an economy and society shattered by eighteen years of war between Justinian’s troops and the Goths.5
If the Western Empire had still been in existence, either independent or fully reunited with Justinian’s realm, as of the 560s, the Lombard invasion would have fallen on their frontiers in Dacia or the middle Danube and been met by a substantial military force in long garrisoned, unruined fortresses rather than the war ravaged Italy of real-life 568. Barring excessive losses due to the 542 plague and its successors, it should have been containable but would have prevented major Western military aid to the East against the Avar threat, or against the less centralised but no less dangerous infiltration of Slav settlers into the ravaged Balkans in the 570s and 580s. The latter ultimately lost the Empire this invaluable centre of troops, supplies, and taxrevenue and thus made it dangerously weak to face the Persian threat after 602 and the Arab threat after 634.
If the Lombards had been contained, the Western Empire should have been able to send Tiberius II and Maurice valuable troops in the 580s to deal with the Avar threat and the Slav settlers, though these smaller groups of invaders would have been more difficult to corner. Crucial fortresses such as Sirmium (lost in 582) and Singidunum (lost in 583) would have been saved, and the middle Danube line been held against major penetration. This would not have prevented the major Avar raids into Thrace from the lower Danube, which had already reached Anchialus in 583 and the ‘Long Wall’ in 584 and led to years of inconclusive Roman campaigns, and increasingly to worrying mutinies by the East’s Balkan armies against their unpopular generals.6
Western military help would not have prevented a multiplicity of raids and the resultant insecurity, flight from the land, and threat to agriculture in the Balkans. But if the West, as overlord of the German tribes who had escaped from Attila’s sons’ control in 454, such as perhaps the Lombards and Gepids, had occupied or dominated Dacia their army would have been able to cross the Carpathian passes and take the Avars in the rear. A nomad people could easily abandon their threatened homeland and retreat across the plains with their horse-drawn waggons, outstripping their lumbering pursuers, as Darius the Great had found in this area in 512BC. Constantine the Great had had more luck in a massive campaign North of the Danube in AD332, aided by local allies, but lost his nerve in 334.7 But a joint Western and Eastern advance on the Avar homeland would have served to keep the raiders on the defensive rather than perpetually raiding Thrace while their Slav allies overran the inland Balkans, and would probably have forced a temporary treaty out of their ‘Khagan’ until he was confident enough to resume the war.
A lesser Balkan threat, no Eastern Roman collapse after 602?
Arguably, the assistance to Maurice’s forces by a Western army –meaning less pressure on the Eastern troops – would have meant less mutinies by the latter, who in real life revolted in 593, 595, and, fatally for Maurice, 602. Generals had to be replaced, the money saving Emperor’s attempts to pay his men in supplies not coin had to be rescinded, and the attempt to winter north of the Danube in Avar territory was defied successfully twice. The strain on the East’s finances was obviously one cause of Maurice’s careful fiscal measures, though his troops preferred to call him stingy, and after he refused to ransom the Avars’ captives, who were massacred, and made a second order to winter north of the Danube, a final revolt led to his overthrow.
The resulting tyranny of the troops’ nominee as Emperor, the centurion Phocas, and civil wars led to Persian intervention and the disasters of the 600s and 610s.8 But it is possible that a less financially stringent Emperor than Maurice would not have been as hated by the troops, or faced a violent uprising in Constantinople in their support when they marched on the capital.
How much of the disastrous success of the 602 mutiny, leading to civil war as various provincial armies challenged Phocas, was due to the brusque, unpopular Emperor? What if his predecessor Tiberius II had not selected him as his chosen son-in-law and heir in 582? Maurice had been an experienced and successful general in the Persian wars before then, but he seems to have been a failure in keeping his troops’ loyalty as shown by repeated mutinies in the 590s. Indeed, the chain of dubiously competent Eastern leadership can be traced back through the profiligate Tiberius II to the previous ruler, Justin II, nephew and successor of Justinian. An irascible and haughty man, his refusal to continue a subsidy to the Avars is supposed to have caused their first attack on the Empire, though such a steppe empire was likely to raid the East at some point. His surprise descent into permanent mental instability in 574 led to his powerful wife Sophia (niece of Theodora and just as ruthless) taking charge of the government and choosing a senior Court regimental commander, Tiberius, as her Caesar and the next ruler. The choice of Justin as Justinian’s heir was doubtful, as the old Emperor died suddenly on 14 November 565 with only his eunuch chamberlain Callinicus’ word for it that he had named Justin at all. The latter was the preferred choice of the two most powerful Imperial female kin, Sophia, and Justin’s mother Vigilantia (Justinian’s sister). They duly hurried him to the Palace to be crowned by Patriarch John before his rivals knew Justinian was dead.9Without this coup, there is a chance that Justinian or his ministers would have preferred another Imperial nephew called Justin, the militarily experienced son of the late Germanus, who in November 565 was away commanding troops in Bithynia. He was sent off to Alexandria as governor and later murdered, probably at Sophia’s orders. Would this other Justin have proved a better Emperor than his namesake, passed the throne on to his heirs, and thus reduced the possibility of a disastrous civil war after 602?
It is probable that the extra bonus of Western aid could have staved off this disaster to the Empire, which ruined its strength and unity ahead of the Arab attacks, though the piecemeal Slav settlement of the Balkans was more difficult to halt than attacks by Avar armies. Hopefully, though the flight of Roman farmers from the land would have transformed the social and economic basis of the Balkan peninsula, and brought in pagans to replace Christians, major towns within reach of the Black Sea and Aegean coasts could have been held and the decentralized Slavs, small groups of settlers lacking warlords or kings, been brought under Roman military control after the Avars had been vanquished. Their menfolk could then have been recruited to the Roman army and settlers moved to under-populated areas elsewhere in the Empire, as Justinian II carried out after 685 in real life, and the pagan tribes been Christianised once the Church interested itself in missionary work.10
The lesser strains of a Balkan war in the 590s might have saved Maurice from overthrow in 602, though losses of manpower and financial capacity due to the plague would have been serious even had the West survived. Maurice, apparently loathed in Constantinople and the object of a massive rising by the united circus factions in 602, or his inexperienced young son Theodosius (III?) would still have been at risk of overthrow at some point. To that extent the Empire would have been luckier had the vigorous if spendthrift Tiberius II (who died in 582 in his early fifties) lived longer or had a son, or had Justinian been survived and succeeded by his competent and popular cousin Germanus, who had sons. Once Maurice’s dynasty had fallen, there was an excuse for his old ally King Chosroes II of Persia, who he had restored to the Persian throne in 591, to invade the Empire out of hostility to his usurping successors. In real life, Chosroes used a pretender to the identity of Prince Theodosius, whose death in the bloodbath of November 602 was less certain than that of his younger brothers. The claimant seems to have had some impact in winning over Roman commanders to ally with Persia in the threatened frontier zone of Mesopotamia, as with ‘Domestic of the East’ Narses at Dara in 603, though dislike and fear of the low-born and increasingly bloodthirsty Phocas would have been other factors.
Arguably, a domestic revolt in Constantinople against Maurice in favour of a more acceptable usurper from the traditional ruling classes, most obviously Theodosius’s father-in-law Germanus, who Maurice accused of treason in 602, or Phocas’ dubious ally Priscus, would have been more likely to command the loyalty of most Eastern army commanders and so kept their command united.11 The Persians would have had less success in breaking through the frontier during Phocas’ reign and thus presenting his replacement Heraclius with disaster in 610: even with the real-life civil wars in the riven Empire, Persia did not gain Dara until 606, Theodosiopolis (the north-eastern frontier key) until 608, and Edessa (key to the upper Euphrates) until 609.12 The nature and beneficiary of the anti-Maurice revolt were thus crucial, but had the Western Empire still been in existence in 602–10 their army would have had the potential to invade at an early stage and remove the usurper. Heraclius, as son and nominee for the throne of the rebelling Exarch of North Africa in Carthage, would have been well placed to use Western aid to reach Constantinople earlier than the real-life autumn 610. The successful invasion of the East by the West had last been carried out in 361 by Julian, though his rival Constantius II had opportunely died before the outcome was decided by battle; Constantine the Great had removed Licinius in 324. Thus Heraclius, or another Western nominee, would have been able to assume the command in the East against Chosroes at an earlier date, and to use Western troops to drive him back.
It is possible that Chosroes, an ambitious ruler who by the 610s was seemingly intent on reconquering all the Levant lost to Persia in 334–1BC but also potentially open to Persian aristocratic resentment for being installed by Roman armies in 591, would have invaded the Empire opportunistically at any point of domestic crisis. The overthrow of his benefactor Maurice was the real-life excuse, but there could have been others; in 540 his predecessor-but-two and namesake Chosroes Anurshirvan (Immortal Soul) had invaded Syria while Justinian was preoccupied in the West. Assuming that a domestic Eastern crisis after 600 led to a Persian invasion and that a long civil war had enabled Chosroes to take the major Mesopotamian defensive fortresses as in real life, the new Emperor installed securely in Constantinople (Heraclius?) could have called on Western aid to drive back Persia. There is a caveat in that the Empire was hit by plague and famine independently of the civil war in 608–9, thus diminishing its ability to raise troops to fight Persia, but we need not doubt that the civil wars in Syria and Egypt between Phocan loyalists and Heraclian attackers in 608–10 aided the Persians’ success in overrunning this war-ravaged area a few years later.13 Antioch and Caesarea-in-Cappadocia only fell to Chosroes’ generals in around 611, Melitene and Damascus in 613, Palestine in 614 (notoriously aided by a Jewish revolt), and Egypt in 617–19; meanwhile the Persians could raid across Asia Minor to Chalcedon in 614 and in 616 two attacks reached Chalcedon and Sardes.14
Thus the major disasters in loss of territory only followed Heraclius’ accession, and they were aided by a renewed Avar war in the Balkans; finally in 626 the two powers were able to attack Constantinople together. Had the Eastern Emperors defeated the Avars decisively, hopefully with Western aid, or Heraclius secured the throne with Western aid at an earlier date the Persian attack should have been blunted before it reached this critical stage. The Eastern Empire would have been fighting on one front not two whenever the Persians attacked, and the latter would have been unlikely to have secured Syria or potentially rebellious Palestine let alone Egypt. The main war between Heraclius, probably with Western aid, and the Persians would have centred on the fortresses of the upper Euphrates and Armenia, sites of the previous Roman-Persian wars in the 520s and 570s, or at worst on an invaded Syria and Cappadocia. Crucially, the amount of damage done to crops, towns, and fortresses ahead of the Arab attacks would have been substantially reduced and there is less chance of the collapse of Roman power leading to inter-communal massacres in Palestine. Thus the area would have been able to meet the new challenge from the desert from a stronger position in 634–6, instead of in the aftermath of thirty years of war and over a decade of foreign occupation.
Assuming a major Persian war to have taken place during an Eastern civil war in Chosroes II’s reign (591–628), the Eastern Emperor, for the sake of argument, Heraclius, could still have lost control of the Euphrates fortresses and faced invasion of Syria. Without the Avar threat as a problem nearer his capital, he would have been able to take the offensive earlier than real-life 626/7. But it is still logical that he would have chosen to invade the Persian heartland via the Caucasus uplands rather than across the Iraqi plains. The Persians and their Parthian predecessors had been able to utilise the latter to harass Roman armies with their hordes of cavalry archers since the disastrous Parthian rout of Crassus at Carrhae in 53BC. The Romans’ nomad Arab ally in Eastern Syria, the Ghassanid confederation, had been destroyed by the pro-Persian Lakhimids recently, so the Emperor could not use their cavalry to protect his army’s flanks against harassment. Quite apart from the uncertain numbers of troops that Chosroes’ generals Shahin and Shahbaraz had at their disposal to oppose a Roman advance, it would have been a wise strategic move for the Emperor to avoid the open plains and march on Chosroes’ capital Ctesiphon via the mountains, and, as in real life, to join up with the new steppe power of the Khazars in the Tbilisi area en route and secure their cavalry. As in real life, the Romans would then have descended on the Iraqi plains from the north (the intended route of Mark Antony in 34 BC) and assaulted Chosroes’ heartland. The speed of the Persian collapse in real-life 627–8 indicates that there was war weariness in their empire as well as in the Roman lands, and it is probable that (as in real life) the humiliated Chosroes would have been deposed and murdered by ambitious relatives and the latter then sued for peace.
Long-term results in the Middle East, effects on the Arab invasions?
The collapse of the war-weakened Persian polity in 628 resulted not only in the evacuation of Roman lands by the undefeated Shahbaraz (who then joined in the competition for the Persian throne) but a prolonged civil war and serious instability. The eventual winner of the conflict, Yazdegerd III, faced Arab invasion in 637 and after losing Iraq, not easy to defend from the Southern desert, as seen by Saddam Hussein in 1991 and 2003, abandoned the fight and fled to the Iranian plateau. Had the area not recently suffered foreign invasion and a prolonged civil war, as with the Roman Levant, Arab occupation would not have been so easy, though the state of the defences of the cities and the morale of their defenders can only be inferred. In the field, the exaggerations of later Arab writers make accurate assessments of Persian numbers impossible. The contemporary Armenian Sebeos put numbers at Qaddisiya at 80,000. One hard-fought battle over several days won all Iraq. Indeed, it is possible that a victorious Eastern Emperor (with Western reinforcements?) could have imposed a treaty on Persia that saw further advances of the Roman frontier from the favourable terms of Maurice’s dictat to the newly-installed Chosroes in 591. The obvious field for Roman expansion was the Caucasus, which had Christian kingdoms in Iberia and Lazica/Abasgia (later to merge in 1000 as Georgia) and the divided Christian land of Armenia. Long torn between Rome and Persia, most of Armenia had passed to Persia in the favourable treaty of 387 and then back to the Empire in 591; the latter treaty had also secured Roman domination of Iberia and a number of valuable fortress-towns in the salient between Euphrates and Tigris (e.g. Nisibis).
The real-life exhausted Empire of 629 was content with a restoration of the ‘status quo’ on the Persian frontier, but an earlier and more crushing victory, aided by Western troops and possibly by vanquished Avar and Slav ‘federates’ from the Danube, could have secured the Empire full control of all the Caucasus region as far as the vital Darial Pass. This invasion-route was the Khazar highway from their steppe homeland to the Kur valley, where Heraclius met their army in real-life 627, and thence on to attack either Persia or Roman Armenia; its control would be vital for the Empire and could have been secured with extra troops. There were also local Christian ‘Alans’ (Ossetians) available to be used as allies, with titles given to their rulers as was the Roman practice for friendly Caucasian notables. It would not be an innovation for Roman policy to extend their rule or influence this far northeast; it had been considered by both Pompey (who had invaded it in person in the mid-60s BC) and Trajan. Nor was Eastern interest in the 620s a unique result of Heraclius’ situation, Justinian had fought hard to keep the Persians from the Black Sea, the two empires clashing over Iberia and Colchis.
Given the previous Roman occupation of Iraq by Trajan in 114–17, it is possible that Heraclius would have annexed it from a supine Persia once Chosroes was dead and his heirs fighting over the throne. The Persians were as vulnerable, perhaps more so, to well-armed, large Roman armies as to the small army, perhaps 7,000 strong, of Arab nomads who invaded in 637, if lacking their concentrated archery. Heraclius used propaganda to stress the religious element of his Persian war and inspire zeal, as the Caliphs did. The Romans would not have had to rebuild an occupied and war-shattered Levant in this scenario, though Syria might well have suffered heavily as in the previous Persian invasions of 260 and 540. But loss of men and tax resources to the plague and Balkan wars would make this extension of Roman territory improbable, and it is more likely that Heraclius would have contented himself with backing up his client Shahbaraz as Maurice had previously backed Chosroes. It is arguable that if the experienced Shahbaraz, soon overthrown in real life, had lasted as Great King he would have made a better job of holding back the Arabs in Iraq than Yazdegerd, with no known military experience, did in 637, defeating the lightly-armed invaders once they moved away from the desert to attack the major towns. A Persian ruler who had no dynastic legitimacy was, however, at risk of overthrow by princely pretenders, though Chosroes’ noble rival Bahram Chobin had lasted until removed by Maurice’s armies. It is possible that Shahbaraz and his successors could have held onto the Iranian heartland by building fortresses and defending the passes that crossed the Zagros, at least for a few decades; in real life the plateau was lost in 650. It is unlikely that a Roman Emperor after Heraclius, in real life his consumptive son Constantine III and under-age grandson Constans II, would have had strategic appreciation of the danger of the Arabs wielding Iraqi manpower and Persian military skills against them, the only reason why the Empire might have been willing to lend its troops to a counter-stroke against the Arabs for Persia’s benefit. The Romans in the 640s had no awareness that the Arab conquest was permanent. The new state could have proved as ephemeral as the last successful desert state, the empire of Palmyra whch Aurelian had destroyed in the early 270s.
Within a few years of 630 the Empire would have faced a rising gradient of Arab incursions into Palestine and Syria, as in real life. This developed independently of the Roman-Persian war, following the Prophet’s uniting of the Arabian Peninsula, as the warlike Arab tribesmen turned their energy from mutual conflict into attacks on their war-weakened nighbours. The consequences for the Empire’s survival of a militarily improved situation in the Levant in the 620s have been covered elsewhere. But the same argument holds as made there, in that no major conflict for the region around 602–29, or an earlier Roman victory would have left fewer towns and fortresses damaged, more troops garrisoning the area, a less ravaged countryside, less mutual antagonism of Jews and Christians in Palestine, and greater will to resist. It would not have prevented military defeats in hostile terrain or bad weather, as at Yarmuk in 636, or the piecemeal undermining of agriculture and isolation of towns by repeated raiding that Roman troops could not prevent. Isolated towns, their trade reduced by insecure roads, could have fallen one by one and farmers have fled the countryside as new settlers took over their lands by force, as the Slavs achieved in the Balkans. But the number of Roman defeats should have been less, and towns, not taken by the Persians, so with undamaged walls, should have held out longer, except when struck by earthquakes.15
It is worth noting that in war-ravaged Italy after 568 the persistent but small and poorly-armed Lombard incursions only gradually overran the isolated towns, and failed to conquer the Southern coastal towns or fortified Rome and marsh-bound Ravenna. Inland, the countryside could be overrun and isolated towns surrounded and starved-out. Could the Arab armies have had a similarly limited effect at first in Syria and Palestine had they faced stronger resistance and the Caliphs diverted their main efforts against the weaker Persia?
Coastal towns should have held out longest as they could be supplied by sea, at least until the Arabs had acquired siege-machinery from Persia; in the thirteenth century the well-defended coastal towns of Palestine and Syria defied the inland Moslem powers for decades. The maximum danger would have come had walls been levelled by earthquakes. Logically, the availability of troops from the Western Empire to assist the Eastern army should have made the latter more formidable, and reinforced their garrisons’ ability to hold out. The one caveat to this is that a Catholic Western Emperor might have take issue with Heraclius or Constans II over their heretical proposals to reunite Nicaen orthodoxy with Monophysitism by a new theological dogma, and thus broken off the supply of military aid for several crucial decades from around 640.
Inland Syria and Palestine were difficult to defend from the desert, although a stronger and well-funded Eastern army should have been able to defeat most lightly-armed Arab armies until the latter had superiority of numbers from the conquest of Iraq and the Iranian plateaus. The threat of Arab archery to Roman infantry or cavalry, as from the Parthians at Carrhae and of inclement weather or incompetent generalship would have aided the Arabs. Roman fear of encounters with their Middle Eastern enemies in the open plains was more noticeable at times of military inferiority. Trajan in the 110s, Lucius Verus in the 160s, Septimius Severus in 197–8, Carus in 283, and Julian in 363 all tackled the open plains of Iraq and the Persians chose to retreat before them. Possibly a major defeat like Yarmuk would have made them as wary of the Arabs as they had been of Persia in the plains in the 620s, or poor leadership after Heraclius died undermined a coherent resistance and led to piecemeal conquest of the Levant. But the Romans had held onto well-fortified Antioch against Parthian attack after Carrhae in the late 50s BC, thanks to decisive leadership by Cassius, later Caesar’s murderer, and superior defensive capability. Could the will to resist and more troops have saved Antioch again in the 640s?
With regular military assistance from the West, not available to the heretic Constans, in real life in conflict with the Papacy, the local outposts of the Eastern Empire could have held out for several more decades, at least on the coast. A fortified ‘limes’ across the line of the Isthmus of Suez and ships, aided by the allied Christian power of Axum, which had had the naval power to hold the Yemen in recent decades, in the Red Sea, could have preserved Egypt for several decades, until the Arabs managed to infiltrate the local deserts and join up with local tribesmen around the Nile valley. It is quite conceivable that the Romans could have halted the Arab advance westwards at the Red Sea or the ‘narrows’ of Tripolitania and preserved most of North Africa for Christianity, at least until some civil war gave the invaders their chance. Western troops from Europe would have aided the resistance around Carthage, though if the Arabs had managed to convert the desert tribes the always latent threat of Berber raids could then have made the province economically unviable and led to eventual evacuation. The limited archaeological evidence in Tunisia for the seventh century shows poor agriculture and declining towns (aided by Berber raids?), so resistance would need outside help.
Most probably, the Eastern Empire would have retained Antioch and the fortresses of upper Iraq for some decades from circa 640 but faced a Caliphate that had taken over all the Iraqi plains and all of Persia and could throw the manpower of the latter and of Arabia against it. The threat would have been more acute than that of Persia, with the prestige of ‘jihad’ encouraging each Caliph to wage war on Rome rather than the Persian Great Kings who were only sporadically aggressive. It is unclear but possible that some of the Arabs living on the Syrian Desert frontier who joined in the invasions were former auxiliaries in the Roman army, which regularly used Arabs, who knew the area well and coveted its land for their herds. An apocryphal story has it that Arab tribes who were normally paid off to avoid raiding Syria by the Roman authorities were refused money by the cashstrapped government and so joined the attack.16 Persistent Arab pressure from a united state keen to win lands and loot is probable.
For the moment, any Roman military success and the frustration of Caliphal plans to settle Arab tribesmen in Syria and Palestine, later in Africa, would have resulted in a heavier settlement by them within conquered Persia. Their military energy, used against each other if there was no external enemy to attack, as seen in successive civil wars in the late 650s and 680s, would still have needed a focus. The new post-civil-war regime of Mu’awiya in the 660s was particularly aggressive in ranging across Asia Minor in real life. Accordingly, Caliphs concerned to direct their troops against an external foe would have had reason to launch them against their Eastern neighbours at times of truce with the Romans. Would this have led to an earlier conquest of Transoxiana and the Indus valley, or even a concerted attack on the Indian sub-continent far earlier than the real-life efforts of Mahmud of Ghazni in the early eleventh century and the Ghaznavids in the later twelfth century? The military adventures of probing and, if successful, conquering Spain and the Indus valley in the early 700s were taken on by local commanders in North Africa and Iran with minimal direction from the Caliph in Damascus, logically to keep their restless troops occupied in the same manner as Attila constantly sought new targets in the mid-fifth century.17 With stronger Roman-led resistance in the Mediterranean, military adventurers could have concentrated on the East.
After the seventh century
More or less permanent Romano-Arab war would follow, on a far more regular basis than Roman-Persian conflict, and duly undermine the Empire’s military and economic capacity. But the Empire would have possession of the Balkans and, usually, Western military aid, and it would be in a better position to resist, and to hold onto Asia Minor and Armenia without major raiding, than the real-life Empire of the later seventh and eighth centuries. It could also take the offensive more easily when the Caliphate began to decline and break up, and if it had held onto Egypt or Tripolitania to block an Arab advance westwards the main area of conflict would have beeen Syria.
Indeed, arguably the successful defence of the Balkans from the Avars and a Western military presence in Illyria and Dacia might have enabled the Eastern Empire to hold the Danube against the Bulgars in the later seventh century. Previous large-scale crossings had been held back by a powerful Eastern army, or at least contained in Thrace, as would have happened with the Goths in 376–8 had Valens not tackled them so precipitously but waited for Western reinforcements. Aided by Western attacks on the Bulgars in the rear from Dacia, Constantine IV might have managed to push out the newcomers in the initial clash of 680. In real life, the Bulgars established a permanent base in the lower Danube valley and threatened the rest of the Balkans. Had the Arabs distracted the Eastern armies from a Balkan war in 680, a stronger Empire could still have blocked the Sredna Gore and Haemus ranges’ passes to more than occasional Bulgar raids. Constantine V’s long campaigns against the Bulgars in the mid-eighth century might then have been successful in evicting them.
Disasters such as Nicephorus I’s defeat and death in a mountain pass trap in 811 would have been less likely in a better-resourced Empire, if still possible in cases of incompetent command. In real life the disaster of 811 brought Bulgar Khan Krum’s armies to the walls of Constantinople and lost most of Thrace and the inner Balkans, a valuable source of Eastern military manpower; a similar Bulgarian domination of the peninsula followed under Czar Simeon in the 920s. Had the East held onto the peninsula, or contained the newcomers north of the Great Balkan range in the Danube plain, it would have had extra resources of manpower and supplies, although arguably not taxes, given that this rural area was not then a monetary economy. It was however likely that large-scale and disruptive raids south would have continued to undermine the economy, send farmers fleeing, and reduce the viability of isolated towns. This had occurred during the sixth century at the hands of Kutrigur Huns and Avars despite all the Empire’s armies. All this would aid the Slav settlement that occurred in the devastated Balkan vacuum in the real-life later sixth and seventh centuries. But logically a more powerful Imperial army would have had the means to coerce these divided and poorlyled settlers into supplying valuable troops to the Empire as Justinian II did in Thrace in the 680s and Irene and Nicephorus I did in Greece around 800.
The Eastern Empire might still have faced a depopulated Balkans. But it would lack the distraction of successive Bulgarian wars as it regained the military initiative during the early to mid-tenth century. The Arabs would have held only a part of the south and east Mediterranean coasts, and been less likely to have had the disruptive advantage of naval power had the Empire held onto Egypt, with Alexandria, or the Syrian coastal ports or both. Crucially, the new Arab fleets which threatened Constantinople in the later seventh century used the forests of south-western Asia Minor and Cyprus for timber; a more powerful Empire holding most of the Levantine ports would have prevented this. The Arabs would not have conquered Sicily and Crete from the 820s, thus releasing the Empire from another military distraction during the following centuries. Even if Egypt, vulnerable to raiding of the Nile valley from the deserts, had eventually been occupied, possibly by a dynamic Caliph with armies from Persia, the Western army would have been able to assist the defence of provinces further west, delaying any advance to Carthage.
Much would depend on whether the East was distracted by a civil war at a time of Arab unity, e.g. under the first Abbasids from around 750 to the 809–13 civil war, and if the restive Berber tribes of the north-western African interior chose to attack a weakened Imperial defensive system. The extent of Roman losses of manpower to the plague, rural disorder or both in the African provinces would have been crucial; it is probable that the cities of this area were in steep decline before the Arab invaders arrived. Carthage, the regional administrative capital, was already shrinking in size before its conquest in 698. The Abbasid polity of Al-Mansur or Harun al-Rashid would have been as great a military threat to the Empire as was the Sassanid Persia of Chosroes II two centuries earlier, but once the Caliphal state was in decline and its outlying provinces were breaking away their military advantage would have ended.
It is not unreasonable to speculate that a competent Eastern military leadership in the tenth century, perhaps Nicephorus Phocas and John Tzimisces, as in real life, would have had the time and resources to reconquer Syria more easily in the 960s and move on against Jerusalem or Baghdad. The Empire was in real life far inferior to the Caliphate in manpower and other resources through the later seventh century into the ninth and had to conduct a holding operation in Asia Minor. It only achieved local military superiority when the Islamic Middle East had broken up into rival states. The enemies who tenth century generals and Emperors, most notably Nicephorus Phocas and John Tzimisces in around 955–76, routed to reconquer Cilicia and Syria were the small if militant Hamdanid emirate of Aleppo, backed up by its allies in Mosul, not a major Caliph-led Iraqi state. Even then, they were distracted by successive Bulgarian wars and the Russian incursion into Bulgaria after 968.
An Empire with full possession of the Balkans, and its menfolk as recruits for its armies from the seventh to the tenth centuries, would have been in a better military position. The Emperors could even have met large Caliphal armies in the field at the time of a united Caliphate without such humiliating defeats as that which Theophilus suffered at the hands of Al-Mutasim in 838. By the mid-tenth century, they would have been able to launch reconquest without Balkan distractions, except perhaps the Russian invasion of the late 960s, launched from an area far beyond Imperial control. It is possible that the remorseless aggression of Basil II, not distracted by the Bulgarians as in real life, would have turned him to Eastern conquest and taken him to advance on the weak regimes now ruling Baghdad. The latter’s Caliphs were under the military control of the aggressive, but usually disunited, new state of the Buyid family, Zagros mountain warlords ruling Western Persia, from the 960s, and hence a new Roman-Persian confrontation over Iraq was likely. The Empire would have had the edge in terms of manpower, but faced serious military difficulties if it had managed to take and hold the Iraqi cities and plains, a familiar problem for Western aggressors from Trajan to George Bush.
The Eastern Empire versus the Turks in the C11th – any difference from reality?
Backed by Western troops and ‘federate’ Russian and steppe nomad allies, the Empire could have advanced its Eastern frontier between 960 and 1025 to conquer all the Levant and Iraq. It would come up against the Turks on the Iranian plateau, the new local nomad power as the Buyid confederacy declined, and face the same military threat there around 1050 as it did in real life further west in the following decade. The Turkish nomad cavalry archers would have been a menace to Roman infantry, in the tradition of desert and steppe opponents since the time of Crassus’ defeat at Carrhae (53 BC). Had the Empire not taken the risk of overrunning Moslem territory beyond its old frontier and restricted its reconquest to Syria and Palestine in the tenth century, then the Turkish advance would have taken the same course as in real life. The Seljuk dynasty, rallying Turkish nomad military resources as the new power on the Iranian plateau and controlling the powerless urban centres, took over control of the Caliphate in Baghdad around 1055, with their ruler as the first Sultan, technically ‘slave of the commander of the faithful’. In reality they reached Armenia and Syria around 1060–70, and this was the probable time-scale for a military confrontation with the Empire had this not occurred earlier over Baghdad.
The Empire would have had more resources than it did in reality, but still been at risk of a major defeat by the Turks’ nomad horsemen, the same type of foe which they had been routed by at Carrhae. It would also have had the same problem in military confrontation as in real life faced Emperor Romanus IV in 1068–71, namely a large, lumbering Roman army, moving at the pace of its baggage-train, endeavouring to deal with small groups of mobile cavalry. Both Byzantines and Crusaders had cavalry in real life, but were seriously harassed by the more manoeuvrable Turkish steppe ponies and by long-range archery. This problem would have faced a hypothetical Eastern Roman army from a larger Empire too, unless a skilled Imperial commander had used his finances to recruit a rival force of nomads such as Magyars or Pechenegs from the Empire’s allies on the Ukrainian steppes. In real life, the Empire did attempt to recruit such troops to face the Turks in the 1050s but they lacked military discipline and often deserted, a probable scenario in any event.
The Eastern and the Western Empires confront the Mongols
As with the Mongol descent via Russia on the West in 1237–41, the sheer numbers involved in the Mongol assault would have made it more formidable than the Turkish invasions and the invaders would also have had Chinese military technology. The latter included siege engines and gunpowder projectiles, which had a psychological as well as physical impact. Even stone walled towns were vulnerable to outright storming or prolonged blockade, as faced by the Moslem frontier towns on the Oxus in 1220 and Baghdad in 1258. The Great Khan, unlike Attila, was interested in submission rather than in being bought off, whether or not his interest in world conquest can be attested reliably. The Empire would have been a prime target although it would have been more unified and better resourced than his real-life victims, the disunited Moslem states of Persia and the Christians of Russia and then eastern Europe. There was also a possibility of this latest incursion of steppe conquerors driving its victims to flee into or attack Roman lands, as the Goths had done ahead of the Huns in the 370s. The Mongol conquest of their first Moslem foe, the Shahdom of Khwarezm in Iran and Transoxania, in the early 1220s drove Shah Mohammed’s son and his armies into seeking new lands in the Levant and Georgia, and any such flight of Moslem forces would have posed a threat to the Empire.
The real-life timing of the Mongol attacks would suggest that the first major Mongol ‘probe’ would come in 1227, with the campaign across Azerbaijan and the Caucasus. Even if the Empire had not been in possession of the former, any attack on its Christian allies in Georgia would have been likely to lead to an attempt to intercept or punish the attackers. A clash was more probable with the Mongol assault on Asia Minor (1243 in real life) or the Baghdad campaign in 1256–8. At the latest, the Mongol move on Syria in 1259–60 would have brought confrontation, with the need of Persian Ilkhan Hulagu to keep his huge armies occupied making long-term co-existence unlikely.
Assuming that the Western Roman Empire had aided the East to defeat the invaders, the Empire would have been freed of its neighbouring Moslem rival with the fall of Baghdad but faced an aggressive new neighbour in the Mongol Ilkhanate in Persia. In real life the Mongols required Christian as well as Moslem rulers, e.g. the kings of Georgia and the Emperors of Trebizond, to become vassals but sought a Christian alliance against the remaining Moslem power, Mameluke Egypt, after their check by the latter at Ain Jalut in Palestine in 1260.
Had the Empire held onto Egypt or regained it before the eleventh century, there would have been no Sultanate in Egypt at war with the Ilkhanate and the probable remaining Moslem power after 1258 would have been centred in Arabia, an even more distant and risky target for a Mongol army. But the danger posed by the aggressively expansionist Mongols to the Roman state would have made the Mongol successor states a major source of anxiety to the Eastern and Western Empires even when the main attacks westwards had ceased around 1260 and the rival Khanates were at odds with each other. A placatory trading mission could have been sent to the remote Great Khan Kubilai in China in the 1260s to establish more friendly relations, and even have involved traders with experience of the Silk Route such as the Polos. But ultimately it is possible that the shock Rome had experienced from the Mongol attacks, a threat of overwhelming force by uncouth barbarians comparable to the assault of the Gauls in 390/87 BC or the Cimbri and Teutones in the 100s BC, would have impressed itself on the Roman imagination as much as the appropriately-named Tatars did on medieval Europe, and produced an argument to take over a declining Persia after circa 1300 to prevent a recurrence.
The past traditions of Roman military action, at least at a time of strong resources, suggest that a pre-emptive attack on a recently hostile polity was logical. This had been seen in the time of Roman pre-eminence, with past attacks on the Gauls in the 50s BC, British (including Caledonian) tribes beyond the current frontier in the first to early third centuries, Dacia in the 100s, and Parthia whenever an Emperor found glory to be politically desirable. The temptation for an ambitious or insecure ruler to prove his military prowess was another factor in recurrent Roman aggression, and the likelihood is that the Empire would not have rested content had the Mongol push westwards been halted with a major battle around 1227 in Iraq or the Caucasus, 1258 in Iraq, or 1260 in Palestine. Co-existence with the Great Khan, the Ilkhan or both by a formal treaty was advisable while they remained militarily strong, as the heirs of the Sassanid state, a military power virtually equal to Rome after around 230. The mutual mistrust of the Mongol states in Persia and the Volga steppes in the later thirteenth century would have made any co-operation between them to fight the Empire unlikely. Luckily for any neighbours, the Golden Horde state on the lower Volga never resumed its aggression against the West of 1237–40 after the death of Great Khan Ogodai in 1241 called its leader Batu back to the steppe to deal with the election of a successor.
But the disunity of the Mongol successor states and decline of the Ilkhanate after around 1300 would have posed a temptation to take over Persian military resources and deny them to another hostile state. Militarily, the declining Mongol state in Persia under Abu Said lacked the leadership to defy its Western neighbour, or any hope of aid from China, and would have fallen, though the Empire might have preferred to rely on local Moslem dynasts as its proxies to expensive outright conquest.
Much would depend on the ambitions of the current Emperor, and the lure of repeating the legendary feats of the conquering Alexander the Great in Persia. But if the frontier was moved eastwards to the Oxus or the Hindu Kush it would pose the problem of how a state based in Constantinople could control lands so distant long-term in an era before telegraph or rail travel, the indispensible aids of the British in their equivalent rule of a farflung Asian land empire. Might the Empire resort to the expedient proposed for Eastern conquests by Constantine the Great, who had also had a large number of male relatives to provide for? In the early 330s he had proposed to hand over conquests from Persia, like Armenia, to his nephew Hannibalianus as one of a number of junior Emperors (‘Caesars’) subject to the overall authority of the supreme ‘Augustus’ in Constantinople. If local dynasts, the real-life Mongol successors in the 1330s such as the Jalyirids and Karts, were not to be made client kings of Persia, an Imperial prince could be enthroned as junior Emperor for the region. The Empire could thus have expanded into Asia on land, and portrayed itself as completing the work of Trajan and Alexander. The size of the Mongol attack could justify ‘pre-emptive’ war.