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An Alternate History of the Roman Empire: The Empire Trapped

By Tim Venning

Bust of Trebonianus Gallus. Photo taken by Francesco Bini, shared under the CC BY 2.5 licence.

This 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 five articles this took us to 251

Both Decius and Gordian II were thus killed in July 251 at the crucial battle of Abrittus near the mouth of the Danube, despite winning the battle and killing Kniva, so the Empire was left with an inexperienced young civilian ruler, Gordian III, in his mid-twenties. Enough Goths got back safely across the Danube with their loot after the Emperor’s death demoralised his army for them to be able to stir up more tribes to try their luck – but only on the lower, not the middle or upper Danube frontiers as the latter held steady . (The surviving German nobles and other charismatic warriors had been enlisted in the Roman army and moved to other frontiers far away – a long-term Roman policy.)

Gordianus III died of the plague early in 252, aged 27. (In real life it was Decius’ surviving son Hostilianus who died; in either case the Empire was leaderless.) At this point the events of 252-3 civil wars occurred largely as happened in OTL, with the leading general then in Rome, ex-consul Trebonianus Gallus, taking the throne early in 252 followed by two military usurpers - Aemilianus and then Valerian. In this version, Gallus was the recently-appointed Praetorian Praefect to succeed the deceased Philip the Arab, stabbed in a scuffle while trying to sort out a violent clash among his Greco-Arab officers, when the plague hit Rome. Gallus took charge when the Emperor fell ill, and on the latter’s death he was chosen as successor by the Palace elite and imposed on the disgruntled but plague-hit and demoralised Senate most of whose members had fled Rome to their country estates so they missed the suddenly-called vote to endorse the ‘election’. Gallus, in his forties, made his teenage son Volusianus co-emperor and co-ordinated quarantine measures and food-relief for the poor, and as the plague hit the harvest of 252 in Italy and not enough farm-workers were left to bring it in (many had not died but fled to the hills) he sent out soldiers to do the harvest and bring waggon-loads of grain to Rome and other major cities.

But while he was busy the Rhine and Danube armies were muttering that they had been left to face the restive Germans with their pay in arrears – tax-collecting was in chaos – and the Emperor had exaggerated the plague crisis, which hit the Mediterranean basin worse, as an excuse for his stinginess. Middle-class ‘new man’ officer Aemilius Aemilianus, the self-made new governor of Lower Moesia, defeated the surviving Goths south of the Danube in late summer 252 as in OTL, but as Kniva had been killed in the battle of Abrittus and lost his main army there (not in OTL) it was a lesser and smaller raiding army that was defeated than in OTL. Hailed as the saviour of the Danube region and having prevented a large-scale pillaging of Thrace, Aemilianus then accepted his troops’ acclamation as Emperor and set off for Rome – taking along a large army of Dacian and Moesian troops so this weakened the frontiers there. Gallus was defeated and killed at Interamna in early summer 253 as Aemilianus entered Italy, and the former’s ally from the Upper Rhine, governor Lucius Egnatius Valerian(us), of a more socially elevated but minor senatorial family from Perusia/Perugia, was too late in arriving to rescue him.

As in OTL, Aemilianus entered Rome with his army after his victory at Interamna - in this version of events, he was the first ‘Emperor created outside Rome’ since AD 69 so it was seen as a major shock to the Empire and his legitimacy was regarded as disputed so this encouraged other provincial generals to revolt. Aemilianus was accepted by the Senate, but was overthrown and killed by his scared and outnumbered troops as he headed North to confront Valerian and the Rhine armies two months later. Valerian then became Emperor, aged 58 and already with an adult son, Gallienus, available to become co-emperor and safeguard the succession. There was no major persecution of the Christians for not sacrificing to the Roman gods as in OTL as the stern traditionalist Decius was only a provincial governor in 249-51 Emperor, and Emperors Gordianus II (242-51, this version) and Gordianus III (242-52, ditto) were more tolerant. But the traditionalist Valerian disliked the Christians for unpatriotically refusing to sacrifice to the ‘genius of the Emperor’ and the protector-gods in the plague of 252 as was declared mandatory to win the gods’ favour, and launched an enquiry into their behaviour as conservative senators demanded to win the latter’s favour. The Emperor did not accept the argument of the arrested and questioned Bishop (‘Pope’) Cornelius of Rome that by refusing to sacrifice they had not insulted the Imperial office and undermined the state but had kept to their beliefs and prayed to their God for the safety of the Emperor and the Empire.

The clergy of Rome itself were rounded up after the enquiry, in early 254, and were told to sacrifice now to give thanks that the plague was over, and all who refused – led by Cornelius – were deported to the outer provinces and had their property confiscated; the Emperor ordered that other clergy in the Empire’s cities who could be shown to have refused to sacrifice in 252 should be treated similarly as traitors, but this was only patchily enforced. There were some executions, led by that of Bishop Cyprian in Carthage, but this was only when the arrested Christians either ‘insulted’ the magistrates or denied the power of the Emperor to coerce them often when goaded into doing this by hostile judges, or were ‘framed’ for insulting remarks about the Roman gods by informers. The ‘persecution’ petered out in 256-7 and the clergy were mostly allowed back to their posts, albeit unofficially and ‘under sufferance’ and minus their confiscated churches so they had to get rich backers to supply new buildings for their services; the patriotic populace, e.g. in Rome itself, remained hostile to them as being to blame for the plague by annoying the gods.

Aureus of emperor Valerian. Shared under the CC BY-SA 3.0 licence.

Valerian remained hostile, but his more thoughtful and intellectual son Gallienus, who had philosophic pretensions and a circle of Platonist friends and clients, secretly invited Christians as well as devotees of the other Eastern ‘Saviour God’ cults to his discussion-groups at his villas when not on duty in Rome or (as in 256-8) serving as supremo of the Lower Rhine armies to punish German raiders and march his troops as far as the Elbe. There was rumoured to be a friendship between Gallienus and the leading Phoenician Christian writer and thinker Origen, a refugee from a plague-era lynch-mob who turned up in Rome in 252 and was living in hiding in Apulia after the 254 deportations when Gallienus heard of and invited him to his local ‘retreat’. Origen was instrumental in persuading Gallienus that the majority of Christians did not insult or despise the Emperor and Empire and just believed in one God and His son the Saviour and were in many ways akin to the contemporary cults of other single gods – and were more socially concerned and egalitarian than many .

There was also a less severe plague than in OTL, so it only had the limited effects of the 160s plague i.e. there was enough manpower for the army and revenue to fund it to stave off a complete ‘meltdown’ or economic dislocation for over-taxed middle class citizens in the towns. Valerian’s reign in 253-60 was less fraught than in OTL, with the Empire’s forces still weakened by plague but less than in reality. There was also less tradition of military revolt recently, so this does not undermine the ability to resist; the eastern Germans (led by the Goths) ravaged the Eastern Balkans in 251-2 and returned in 256-7, but this second wave of attacks on Moesia was driven off like the first had been and quicker. There was no trouble in the Western Balkans with the frontier at the Carpathians, and Gallienus’ expedition to the Elbe taught the lower Rhine Germans to respect Rome again and secured tribute and a large contingent of warriors for the plague-hit Roman army. It was ‘Marcomannia’ which was ravaged in the late 250s not the middle Danube as in OTL, as troops there were reduced to meet the Persian threat after Ardashir’s son Shapur attacked Upper Mesopotamia and took Nisibis and some middle Euphrates towns in 253 . There was only one Germanic naval descent on Asia Minor across the Euxine, from Thrace in 256, led by the Borani (from OTL Moldavia), which used hijacked merchant -ships from the local Roman merchants and the allied Crimean kingdom of Bosporus to transport several thousand raiders round the lower Danube defences and across the Black Sea to pillage coastal towns in Pontus. As in OTL, this expedition was met and seen off by a local Roman force collected by governor Successianus at Pityus; the Bosporan fleet came across the Euxine to aid Rome and the invaders were caught and wiped out. This saw off the naval threat, and unlike in OTL there was no subsequent Gothic attack by sea from 257 onwards and the ravaging of Bithynia and later Greece (including Athens) in OTL 250s and 260s did not occur. The psychological shock of the invasions and the flight of tax-paying farmers from the land was thus less, the government had more cash to keep troops loyal – and there was no civil war among rival local Roman commanders in the region either unlike OTL.

The Romans were able to put up a stronger showing on land in the Balkans, and the 256 attack by sea led to a reinvigoration of a local Roman navy in the Euxine, based at Byzantium and Trapezus and with impressed civilian shipping backed up by newly-built war-galleys, to set up patrols and catch seaborne raiders. There was a recurrence of the plague in 258-9 that slowed up this programme , but this was not as severe as in OTL and without any current land or sea invasions (unlike in OTL) this did not pose a military problem and the main result was a fall in agricultural production and tax-yields. Thus the cities, agricultural resources, manpower, and tax-raising abilities of the Empire survived better and the armies were stronger than in OTL. But the sudden Persian attack by the opportunist ‘Great King’ Shapur on Upper Mesopotamia in 260 was as in OTL, with the Sassanids keen to retake as much of the old Levantine territories of their alleged models, their Achaemenid predecessors Darius and Xerxes in the late C6th and C5th BC, as possible. A new Achaemenid realm would cement their legitimacy with the Persian nobility and the formerly autonomous regional nobles and sub-kings of Media, Atropatene (Azerbaijan), and Mesopotamia, many of whom regretted the loss of the less centralised Parthian state.

Valerian had to take an army East and leave the Rhine and Danube defences to his son and co-ruler Gallienus. He was short of men as in real life, but largely due to having to leave many troops on guard on the Danube and in Dacia not primarily due to plague. He lacked troops who were experienced in fighting the armoured Persian cavalry and recent tax-losses had led to a halt in his original plan to create a large new ‘heavy cavalry’ army for the East; as a result he was too cautious about a head-on clash and was alarmed by the success of the Persian cavalry in breaking through Roman ranks in their initial clashes as he arrived on the upper Euphrates and faced a larger than expected Persian army. The latter was reported as including thousands of ferocious and expert steppe cavalry from the Oxus and Jaxartes plains (OTL Uzbekistan etc) hired by Shapur, and Valerian feared a disaster on the scale of Carrhae in 53 BC if he tried to pursue the ‘retreating’ Shapur across the plains near Edessa and was then surrounded. He had sent to his son on the Rhine and the armies in Dacia for reinforcements, but these were too slow in coming and a new threat from the latest Gothic warlord to attack Dacia if he was not paid off led to the cash-strapped local governors only sending half of the numbers of troops East that they had been told to do. This was not ‘treason’ as Valerian fumed; many of the locally-based soldiers had farms and families to protect, and they refused to march East and leave these to be plundered so their officers had to accept their vocal demands to prevent mutiny.

Valerian agreed to a truce-meeting with the Persians near Edessa in summer 260 as in OTL, as a way to buy time. He was supposed to meet Shapur himself, but was captured by a trick by Shapur’s generals as a large Persian party emerged from a hidden gully and attacked his escourt. His men broke and ran, and he was rounded up and taken to Shapur’s camp with those few who remained to fight for him; the shock reverberated through the Empire and the disgrace of an Emperor being captured led to seditious comments in the Senate that the god had deserted him as he was a usurper. He was speedily ‘deposed’ by his generals in his absence, in an effort to stop Shapur demanding a huge ransom or enforcing a humiliating treaty on him – if he was not the Emperor any longer he was worthless as a hostage, Rome came first not the man who happened to lead it, and if he had to surrender vital frontier cities as expected the Persians would be able to overrun Syria.

Some generals at his ‘base camp’ at Edessa argued that they should keep Gallienus as Emperor and others preferred to claim the throne themselves, and they could not agree on what to do ; but they did agree that it was hopeless to fight the enemy now as their soldiers were demoralised and they retreated into Syria to the refuge of fortified cities on the upper Euphrates, leaving Edessa and the frontier to be overrun. Valerian, expecting to be ransomed by his officers and/ or forced to hand over all of Upper Mesopotamia to Shapur, was told by his annoyed captor that he had been deposed and his army had deserted him and would not negotiate. He was offered a role as a puppet-ruler of the East as a Persian vassal, refused, and was deported to Persia in chains as a hostage and kept in a grim prison fort near Ctesiphon in case he should still prove useful to his captor. He was never heard of again in Rome and died some time in the mid-260s; rumour had it that Shapur then stuffed his body as a trophy and put it on display. Rome faced disaster – but not as bad as in OTL when the Rhine army mutinied and killed Gallienus’ son and heir as he tried to make them leave their own homes at risk of local Grmna attack and assist him in defending Italy and the Balkans. Nor does this version of events have as many local rebel commanders set up as emperors in the chaos of 260, so the central Roman regime has less enemies to handle at once.


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.


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