An Alternate History of the Roman Empire: Julian the new Alexander?

By Tim Vennings


This long Series of Articles discusses a hypothetical history of the Roman Empire wherein Marcus Aurelius lives longer and so it's more stable. In the first nineteen articles this took us to 363. We join the story in the reign of the pagan Emperor Julian, as he prepares to march East.


Simurgh (imperial emblem) of Persia

On the 1st of January 363 Julian, and his senior general Sallustk assumed the consulship at Antioch, amidst riots over the shortage of grain in city. Julian gathered a large army to invade Persia with detachments sent from the Danube, Dacia, Marcomania, and the Rhine, and wrote “Against the Galileans” against the Christians. His ‘Count of the Sacred Largesses’ (finance minister) Felix, who was drawing up the funding of the invasion, died and was succeeded by Rufinus Aradius; meanwhile the turbulent and Arian-baiting Athanasius was expelled from Alexandria once again for stirring up riots by the orthodox. On the 5th of March Julian left Antioch; he halted at Carrhae to sacrifice to the local cult-centre of the Moon, a goddess of ancient Syrian origin whose cult he now showered with money to hire new priests and conduct inspiring and munificent public fesitvals, and, as his older wife Helena (now 42) had not given him any children, is said to have told his maternal cousin Procopius to seize the throne if he died on campaign. His army – around 60,000 and the largest seen since Aurelian’s invasion, the official paperwork and accounts of which Julian took with him as a model - and Euphrates fleet reached Circusium and constructed a bridge of boats across the River Khabur.


On the 6th of April they crossed the frontier, and they descended the Euphrates with Julian commanding the main body of infantry, Nevitta the right wing, Arintheus and the defecting Persian Prince Hormisdas the left wing, and Victor and Dagalaiphus the rear. On the 12th of April the fort of Anatha on the river surrendered to Julian after an appeal to the garrison from Prince Hormisdas. Soon after, Perisabora was besieged, and the defenders abandoned the undermined walls and retire into citadel. Julian joined in a vain assault on the gate which was driven back in a hail of missiles, attempting to emulate Alexander the Great by leading from the front, but it wasn't until his huge siege-tower was wheeled into place that the defenders surrendered.


The Romans had to construct bridges over flooded fields on the lower Euphrates where the outnumbered and retreating Persians had opened dykes, and besieged Mauzamalcha in mid-May. Julian fought in combat against a Persian sortie aimed at him and achieved success in showing what he could do in one-to-one encounters, boosting his men’s confidence in him (not many of his current army had been on his 350s Rhine expeditions as he had left most of this army to garrison the Rhine and Marcomannia and hold back any German attacks). Once siege-engines were in place the walls were undermined, and a two-day assault led to the collapse of a section of the wall and the storming of the town; the Persian army under Suren kept back and did not oppose the advance.

The Romans crossed via canals from the middle Euphrates to the Tigris at Ctesiphon, avoiding the main Persian infantry force that was awaiting them on a level site near the declining and half-empty city of Babylon hoping for a battle, while Julian’s cousin Procopius marched down the Tigris via Adiabene with 30,000 more troops and a large cavalry detachment of allied Alans from the steppes and joined the Emperor near the capital. The Persians were driven back in an engagement at the crossing of the final canal, and their capital was besieged. Arintheus and Jovian protected the vital supply-route back up the Euphrates to the frontier, and as the walls of Ctesiphon started to crumble to the rocks hurled by Julian’s catapults ‘Great King’ Shapur yielded to the appeals of his more belligerent generals and advanced to try to relieve the city. On the 17th of July the Persians were routed in a classic ‘set-piece’ battle outside Ctesiphon as Julian dusted off an old battle-plan of Aurelian’s and lured them into an infantry advance onto his retreating centre and then attacked them in the flanks with heavy cavalry and a shower of arrows.


A wave of Roman light horsemen dragging flaming logs between them smashed into the Persian heavy infantry while their cavalry on the outer wings were lured by ‘retreating’ Roman cavalry into charging into a series of concealed pits, and as the Persians fell back in disorder Julian ordered a general advance and crushed their infantry in a series of charges and probes by heavily-armed ‘wedges’ into their ranks. The Persians lost around 20,000 men to the Romans’ 8000 or so and had to abandon their camp, and with Shapur in flight through the Zagros passes to Istakr Julian was able to secure the surrender of abandoned Ctesiphon on the 23rd of July and soon occupied the Great King’s palace. The city was plundered and a large number of slaves carried off, but for once the Romans were intent on occupation long-term not just on a morale-boosting sacking.


As a result, the local Greco-Aramaic population, who had lived in Ctesiphon and the old Parthian capital of Seleucia nearby for centuries, were not harmed but were instead given protected legal status and employed to run the captured cities in alliance with a permanent Roman garrison and administration. Even the local Christians, descended from the early 4th century Syrian refugees from Diocletain, were called on to help the Empire and promised toleration and the large Jewish population were enrolled to provide their financial expertise as merchants to keep up the trade to India and as bureaucrats to staff the new regional Imperial treasury – the use of Jews, the ‘enemies of Christ’, in the new administration duly infuriated hard-line Catholics back in the main Empire. As the Emperor marched downriver to the great port of Charax to have a new dock built there named after himself and announced the new province of ‘Mesopotamia Ulterior’, to be governed by Jovinus, it was clear that Rome had come to stay and the Emperor was confident that due to the Oriental trade-route and the fertile cornfields between the two great rivers it could pay for itself and feed his new garrisons – which were to amount to some 20,000 men in three legions, plus around 10,000 mostly Arab and Alan auxiliaries on the Eastern frontier.

9th-century painting of Julian near Ctesiphon

But the Persians expected to be able to hold out in the Zagros and to be able to launch attacks in 364 and make the new province ungovernable meaning that Julian would have no more success than Trajan. They were accordingly discomfited when Julian used Aurelian’s abortive plans to lead a large, self-supporting and mostly cavalry force into Media that September to link up with local nobles who had promised or been sent bribes to back Hormisdas. The local loyalist Persian noble cavalry were driven back and with the Alans burning the countryside the populace fled into the walled city of Ecbatana which duly ran short of supplies when Julian besieged it. The city surrendered within days of his huge siege-train, protected by well-armed infantry and Arab horsemen arriving there in early October. By a mixture of luck and his local links with Hormisdas’ allies he had foiled the Persian plan to get him bogged down over the winter in a siege of Ecbatana and then starve out his camp.


As a result, by the time that the usual snows fell on the Iranian plateau Julian had control of much of Media, at least the main towns and cities, and his army in Mesopotamia had taken Susa and marched up to the fortified Persian Gates pass so Shapur could not leave this threat to his Eastern and dynastic capital alone and send troops to Media. In spring 364 Julian proceeded to launch a major, mostly cavalry campaign in Media to secure that area that still held out while his infantry and siege-trains dealt with resisting towns and set up a network of garrisons. The mobile Imperial cavalry held back the northern Persian army at the Caspian Gates pass so they could not rescue Shapur, and in June 364 Julian marched South Eeast into the Persian heartland and bypassed the Persian Gates to attack Istakr from the North West. The main Persian army at the Gates was forced to move back to protect Istakr and after it had left the heights of the Gates were taken in a sudden attack at night by Roman – mostly Armenian - mountaineers, and a second ‘set-piece’ battle on the plain before Istakr saw Shapur routed again by a mixture of an infantry encirclement and cavalry charges onto his flanks.

The Persian elite either gave in and sued for peace to save their lands or fled into Bactria, and the Emperor was able to impose Hormisdas as his vassal-king and have a treaty signed in August 364 wherein the Sassanid empire was broken up into a looser federation of states as Aurelian had intended to do. The Romans annexed all of Mesoptamia and set up a chain of fortresses from the Persian Gates North West along the Zagros passes as far as Atropatene, which now became a Roman vassal under a Rome-imposed king, and Media and Hyrcania were made Roman vassal-states and provided troops and tribute for the Roman army to help fund the occupation of Mesopotamia.


(In OTL, Julian saw initial success but was killed in battle at Samarra and his army surrendered, resulting in Persia becoming the major power of the near east. Here, centuries of Rome doing slightly better and Persia slightly worse tip the balance and Julian wins.)


As with the Germans and their infantry on the Rhine and in Marcomannia, the former enemy now supplied their main forces of war to the Roman army and this undercut their ability to wage future wars, and with a large contingent of Persian and Median cavalry joining the Imperial army every year many of the Persian nobles in these regions were now sucked into the Roman military ‘career structure’ while the civilian population of lower Mesopotamia benefited from the end of the frequent Persian civil wars and of Roman raids. As the self-declared ‘New Alexander’ Julian, flushed with success, had the ultimate aim of conquering all of Persia and so reaching the Oxus and Indus, but for the moment he was content to absorb his new conquests. He stressed in his propaganda that the gods had favoured him in war so they clearly backed his policy of reining in Christian expansion and putting the ‘Galileans’ in their place. After all, he had achieved what Constantine ‘the Great’ had failed to do so the god had clearly punished the ‘Thirteenth Apostle’ for his presumption and his disloyalty to the traditional religion.


In Julian's view it was that religion that had brought Rome victory in the East again, and when Julian had crowned Hormidas as his vassal-king at Istakr in September 364 he set off back for the West and, as events turned out, never returned. The new and large military presence in Mesopotamia and on the Zagros and the Roman auxiliaries lent to Media, Atropatene, and Hyrcania every year to fend off Persian or Persian-allied steppe attacks presented an implicit security risk in case of a revolt so Julian had to balance the new command at Ctesiphon with an equally large military command further up the Tigris at rebuilt camps at Nineveh and Arbela, and both forces were in turn watched by an equally-sized army in Syria based at Antioch and Callinicum. The civilian bureaucracy of the new Roman region was headed by a ‘Praefect of Mesopotamia’ at Ctesiphon, equal in rank to the Praefect of ‘Oriens’ at Antioch, and the staff were to be a mixture of regularly rotated Roman officials and local Greek-speaking Greco-Aramaics and Jews.


The extra cost of the advance of the frontier caused concern in the bureaucracy at Rome and Constantinople and was supposed to be met by the agricultural revenues of the Iraqi plains and the customs on the trade from India, but this took some years to materialise while the refugee Shapur continued to hold out as an independent Sassanid ruler in Bactria, supported by local Turkish tribes which came to dominate his precarious new kingdom – though this served to distract the shaky regime of Hormisdas from challenging Julian as many of his nobles wanted. But for the moment, the Empire had won – and Julian was duly able to celebrate his victory at Antioch in April of 365 with a Triumph not seen there since the Seleucid days.

The news that after over 130 years Rome had finally seen off the threat of Persia as a major power and Julian had achieved Trajan’s and Aurelian’s plans led to an upsurge of patriotic pride across the Empire and a mixture of relief by the pagans that the gods had seemingly showed themselves to be on his side and dismay by the Christian zealots. This was especially true of Athanasius who had been predicting disaster and even saying that the pagan Persians would be the instruments of God’s vengeance on the blasphemous Emperor as Cyrus the Persian had been on Nebuchadnezzar in the Old Testament. The pagan authorities in Alexandria tried to find out if the fulminating exiled bishop had been encouraging the Persians or Christians in the army to have Julian assassinated, but nothing was ever proved. Regardless, for reasons of security, Athanasius was deported to a remote oasis and left there to spend the remainder of his life well away from his rowdy urban allies.


In the event he was able to pose as a martyr and set up a new monastery for fervent Catholics there and this achieved as many recruits as the less ‘political’ and aggressive St Anhony had done half a century earlier at his own foundation some miles away, but, as this was not a security threat, Julian left it alone. Other clerics who had been caught attacking the Emperor and his Persian campaign in sermons or writings also ended up in remote rural exile in the later 360s and were able to set up new monasteries in their new residences. Ironically the Imperial ‘push’ to drive them out of the cities led to the foundation of many famous and well-staffed monasteries across Egypt, Syria, Palestine, Phoenicia, and to a lesser extent Asia Minor. Some more moderate bishops grudgingly accepted that the Christian God had apparently allowed the ‘heretic and apostate’ to succeed, presumably as he was following Constantine’s secular policies and protecting his people, and they settled down to try to hold out until the son-less Emperor was finally struck down for his sins and they could have a Christian ruler again. These more acceptable figures, who Julian did not harass, included one of his own fellow-ex-students at Athens in the mid-350s, the learned and non-political Bishop (St) Basil of Caesarea-in-Cappadocia who was a major founder of local monasteries and schools, and angry religious zealots implied that he was left alone and never prosecuted by the Emperor as he was an old friend and had been ‘bought off’ by him.

The Emperor notably did not bother to hurry back to the West or hold his Triumph in Rome. In his stead, the new consul Julius Aemilius Olympiodorus, a leading civic pagan of ancient family and currently City Praefect, was able to hold a lavish round of festivities and pagan sacrifices and feasts to all of the Olympians on twelve successive days of festival with Imperial support as a form of thanksgiving for the victory in the January of 365. A month of Games in the Circus Maximus followed, and the embattled but defiant Christian community there suffered another setback later in the year when Pope Liberius died and his successor’s election was disputed and caused inter-factional battles in the streets around the Lateran Palace. The majority candidate of the clergy, Damasus, was chased out of the next-door Basilica of St John Lateran during his inauguration by a mob backing his rival Ursicinus and had to use reinforcements from other Italian cities to hold onto his palace and later to regain control of the Basilica. The pagan civic authorities stood by and watched the riots spread disenchantment with the higher clergy’s politics before expelling the leading troublemakers from Rome and confiscating some riot-leading clerics’ churches and other property, and when Julian heard he made the most of this episode in sarcastic diatribes about the hypocrisy and violence of the Christian community.


Damasus had to pay a large fine for disturbing the peace and lost many of the privileges and estates which Constantine had given his Church, though the next Emperor (Valentinian) was to return them in 376, and the resulting exiles of a number of leading Roman clerics from Italy and the break-up of their estates kept the local Church weak and on the financial defensive for a decade with their confiscated estates handed to local pagan priesthoods. Julia himself was too busy with a morale-boosting tour of Egypt to sail up the Nile to Aswan and lavish funds on and recruit young volunteers for the local priesthoods in March-October 367 to bother visiting Italy, and he also used the occasion to launch a military demonstration against the kingdom of Nubia further up the Nile for not stopping raids on the frontier by the desert Blemmydes tribes and led a combined land expedition and naval flotilla upriver to the Nubian capital of Meroe to force a more advantageous treaty out of its king.

This was more of a case of training his largely new army of recent and mostly young Western (especially German) and Eastern (especially Syrian, Armenian and Median) recruits under his veteran generals Arintheus, Dagalaiphus and Victor than a serious campaign as the outnumbered Nubians were not expected to fight and had no weapons to match his anyway. After securing advantageous trade-terms and an enlarged annual tribute in the subsequent treaty Julian carefully installed a new force of local farmer-soldiers as ‘limitanei’ on the Southern frontier to fight off raiders with the aid of new regiments of hired Arab cavalry and moved some surrendered Blemmydes off to Jordan and eastern Syria to patrol the desert frontier there. After a winter in Alexandria to lead pagan festivals and enlarge and extend funding of the pagan-run university there (based at the old site of the Great Library, now rather run-down, in the Museion quarter) in 367-8 Julian headed back by sea to Italy.


Statue of Jupiter, Vatican, Rome. Photo by Biser Todorov and shared under the CC BY 4.0 licence.

In late summer 368, he finally paid a belated visit to Rome for lavish pagan ceremonies and a month of Games, culminating with the ceremonial reopening of the refurbished Temple of Jupiter on the Capitol where he now notably extended the priesthood of Jupiter – a remote figure to many pagans and not linked to any mystic cult of a ‘Saviour God’ or to any intellectual ideology – to include that of the ‘Genius of Rome’ . The current –and pagan – Praefect of Rome, the ‘old family’ aristocrat Vettius Agorius Pretextatus who had family connections with a large section of the old capital’s nobility, led the sacrifices with the Emperor and announced his own sponsorship of a new school in Rome to train priests in the cults of the Olympians ready to serve in temples across Italy, and from then on the Praefect acted as the Emperor’s ‘man on the spot’ to supervise the cults in Rome and see that the Church was pushed aside in the allotment of time and space for official processions. Pope Damasus ended up spending a year in exile in Epirus on Julian’s orders for objecting to having all the post-320s official processions in Rome connected to the cults of Saints Peter and Paul cancelled and, though the bishopric was allowed to keep the Lateran palace, it now had to pay rent for it and this was used, as a deliberate insult, to pay pagan priests at the Temple of Venus and Rome East of the Palatine where Julian now set up rival ‘attraction’ processions and ceremonies. The ‘High Priest of Venus and Rome’, as also the official priest of the cult of the ‘Divine Augustus’, was now the head of a revived cult to celebrate the ideals and successes of the ‘Founding Emperor’ on whom Julian part- modelled himself, his other main models being Hadrian and Marcus Aurelius, and the super-rich and ancient Anicii dynasty (currently headed by Petronius Probus who served six terms as Praefect of Rome between 362 and 386) provided the ‘High Priests’ and much of he funding for this.

Jupiter, the old Italian equivalent of the Greek supreme god Zeus was now hailed in Imperial ideology as the ‘Supreme Being’, to link him to that figure of Platonic intellectual writings. Julian presented him as the benign patron of Rome and its success since its earliest days, but he could not establish any new enthusiasm for the cults of the Olympians in Rome among the populace except practical enthusiasm for their public festivities and a patriotic and possessive devotion to their cults’ annual rounds of rituals by the nobility-run priesthoods. Nor did his expressed enthusiasm for the venerable ‘classics’ of Ancient Greek theatre from the 5th century BC and revival of their main plays for an annual festival held on the Feast of Apollo each year, connected to the Ludi Apollinares (racing) Games, lead to any competent new dramatists arising. This was despite the way he offered rewards for suitable plays to be put on each year and also held an annual drama-festival on the feast-day wherever he was in the Empire from 369 onwards. Despite the lack of new plays, his patronage of theatrical festivals in Greece and funding for the main theatres at Athens, Epidaurus, and Delphi from the end of the Persian war onwards did lead to more theatrical companies being set up to perform the existing repertoire.

While in Mediolanum for the winter of 368-9 he had less success in reviving local (Cisalpine Gallic) nature-god cults there –something he also struggled with in his subsequent tour of Gaul and the upper Rhine region in 369 ahead of his summer 369 military manoeuvres at Moguntiacum. The Western half of the Empire had largely been at peace during the Persian war thanks to him leaving many of the troops experienced in the 350s campaigns to guard the Rhine and Carpathians and his insistence on the Franks, Alemanni, Vandals, and Goths all sending large mercenary levies and the sons of leading nobles to serve in his Persian campaign to remove potential invading warriors from the region.


The one challenge to this came from Irish warlords beyond the seas West of Britain. A loose network of kingdoms owing allegiance to a precarious ‘High Kingship’ based at the fortress of Tara in Midhe, that had been headed in the 340s to early 360s by the unifying warlord Cormac Mac Nessa, had been raiding western Britain sporadically in ‘hit and run’ raids in the summers of the past two decades. In 367 they had proved a major nuisance while many of the usual Roman coastal troops had had to go off to the East coast to help the denuded ‘Saxon Shore’ troops tackle a series of raids on North Sea shipping and coastal settlements in the areas of the Coritani (Lincolnshire) and Brigantes (Yorkshire and County Durham). Count Nectaridus of Britain, the overall regional commander, had ben caught unawares by the descent of dozens of warships from the East Irish kingdom of Leinster on the British coasts of Venedotia (West Gwynedd) and Carvetia (the Lake District). When the first troops sent to intercept them failed he had hurried there himself and ended up ambushed and killed miles from the coast.


The Hadrian’s Wall troops had marched quickly SW from Luguvallium (Carlisle) to the rescue and prevented the Irish raiding further. But this was still a major setback that had been a shock to the West and the need to send half the Classis Britannia from the Channel to the Irish Sea to pursue the Irish (who almost all escaped in their small, fast ships) had prevented the fleet from dealing with the Saxon pirates adequately either. To add to the problems the departure of troops from the West end of the Wall had led to the Picts joining in the ‘triple barbarian attack’, as it was called, and they had overthrown the pro-Roman lords of the Damnonii and Selgovae in South West Caledonia and burnt farms and seized slaves as far as the outskirts of Luguvallium.


(This is a version of what in OTL was known as 'The Great Conspiracy'. Since in this timeline Julian has not died and the Roman position is stronger, the Empire is able to respond more vigorously and the situation is less dire.)

In 368 Julian had had to dispatch a ‘rescue force’ of 20,000 new troops from the Rhine and Gaul to Britain led by the rising and capable Spanish commander Count Theodosius. This army had enlarged the garrisons of Hadrian’s Wall and restored full Roman control as far as the Antonine Wall in 368 and in 369 Theodosius had installed two new pro-Roman warlords as ‘kings’ of the tribes South of the Antonine Wall – Clemens for the Damnonii on the Cluta (Clyde) and Paternus for the Votadini (Lothian) and had campaigned North over the Firth of Forth to punish the Picts and chase them back into the Highlands. In addition, a new ‘Hibernian Sea fleet’, ‘Classis Hibernica’, was built or imported and was set up at a new naval base at Deva (Chester). In 370 Julian arrived in Britain with more Rhine troops to repeat Septimius Severus’ campaign of 210-11 on the Tay and up to the Caledonian Dee and force the Picts into vassalage again. Once he was satisfied that the Northern frontier was safe he proceeded to Venedotia to build a new line of anti-piracy forts down the West coast from the new main army and fleet HQ of Segontium (Caernarfon) where a major new fortress was built. The latter soon came under the control of a dynamic and popular new commander, the Spaniard Magnus Maximus who was a countryman and protégé of Theodosius – and was later to be Emperor – and who married into a local noble dynasty.

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Timothy Venning is a respected Historian who won the London University History Prize in 1979 and whose latest straight history book is Cromwell's Failed State. He has also written multiple books of counter factual essays including Caesars of the Bosphorus, Eternal Caesars, King Charles or King Oliver and King Henry IX, all published by Sea Lion Press, and If Rome Hadn't Fallen.