Rome’s Crisis in the 3rd Century: A Look at 7 Key Events in History

Violent political instability, enemies spilling across faltering imperial borders, and twenty-four emperors in 50 years; this is the story of Rome’s turbulent crisis of the third century.

Jun 29, 2021By Kieren Johns, PhD Classics & Ancient History
Crisis third century overview key events
Details of the Portnoaccio Sarcophagus, c. AD 180, Palazzo Massimo, Rome, photographed by author


Writing in the first half of the third century, the Bishop of Carthage in North Africa, the future saint Cyprian, sought to refute claims of a certain Demetrius that Christianity was the cause of the evils that plagued the Roman Empire. While the search for answers as to what happened during the tumultuous five decades between AD 235 and 284, when the Roman Empire seemingly tottered on the brink, should perhaps approach such theological rhetoric with caution, the bishop provides an evocative account of a world torn in a maelstrom of chaos.


The pieces of an ageing world fall apart… wars continue to be even more frequent, sterility and hunger heighten disquiet, ghastly illness ravages men’s health, the human race is devastated by rampaging decay, and you should know that this was all predicted…”


In modern historical scholarship, the period AD 235 to 284 is broadly referred to as the Crisis of the Third Century. This is a somewhat unhelpful term, as its parameters are too broad and undefined to give an accurate reflection of historical events. Nevertheless, these were decades in which the Roman Empire suffered. Enemies massed and spilled over its borders. In the centers of power, a succession of soldier emperors – characterized in their portraits with square heads, military crew cuts, and surly countenances – were unable to exert any lasting control. The Roman state was wracked from within and without. External burdens ramped up the pressure on these men, while  rivals, pretenders, and usurpers declared for themselves In the space of five decades, there were some twenty-four emperors and change inevitably demands explanation. This is the story of the third-century crisis, told through some of its most influential individuals.


1. The Crisis of the Third Century Begins: Maximinus and the Mummy’s Boy 

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Portrait bus of Alexander Severus, AD 230-235, Met Museum, New York; with portrait bust of Julia Mammaea, AD 192-235, British Museum, London


The events of the crisis of the third century are made ever more surprising after considering the events of the second. The emperors who had reigned over the empire between c. AD 98-180 have long been assured of their historical legacy as presiding over the Empire’s Golden Age’. Trajan had expanded the empire to its greatest point, Hadrian had helped Classical culture flourish, and Marcus Aurelius was a paragon of imperial virtue. Even Septimius Severus, despite his more chequered legacy, had endeavored to leave the empire in rude health.


However, the decades following Severus’ death were marked by new approaches to empire and emperorship and new problems to face. The attempts of his son, Caracalla, to rely solely on the support of the armies of Empire had proved ultimately futile. The civil war that followed gave rise to the accession of one Elagabalus. This young man from Syria, priest of the sun-cult and reputed debauchee, was elevated on the basis of spurious dynastic claims, and his reign was brief. He was succeeded in AD 222 by his cousin, renamed Alexander Severus (ever more tenuous dynasticism on display), and he was tasked with righting the Roman Empire once more.

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Gold Aureus of Alexander Severus, with reverse depiction of Jupiter, AD 224, British Museum, London


For a while, Alexander was successful. The young man returned to a traditional style of rulership, seeking the senate’s active participation and relying on the experience of certain prominent administrators to compliment his youthfulness. The administrators also included the famous jurist Ulpian. He was also, reputedly under the sway of his mother, Julia Mammaea, an influence not well received by the traditionally patriarchal Roman society.


The vestiges of Elagabalus’ debaucheries were removed from the Roman map, including the destruction of his portraits and erasure of his name, a practice known now as damnatio memoriae. For the Historia Augusta, a collection of pointedly allusive biographies written in the late fourth century (and of dubious value as historical evidence), Alexander was a “mirror of princes”, presented in stark contrast to the failings of his cousin. However, even now, there are veiled hints of trouble brewing: Cassius’ Dio’s historical narrative ends mid-way through Alexander’s reign, but hints of unrest across the empire are made clear.


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Silver denarius of Maximinus Thrax, with depiction of personified Fides, AD 235, American Numismatic Society


The problems for Alexander mounted in the years that followed. In a crisis that presaged the turbulences of the third century, violence erupted in the east. The rise of the Sassanids in Persia, led by Ardashir, meant that Rome was facing a severe threat to its eastern frontier once more.


Roman Emperors were honor-bound to protect the Empire. So, with a heavy heart and tears in his eyes, Alexander set forth from Rome to the east. Diplomacy failed, and the military campaign that followed appears to have been abortive (according to Herodian at least, as the accounts vary). It was not to be the end of Alexander’s time on the frontiers. He was compelled to travel north to the Germanic borders in 234 to meet insurgencies from across the limes. His plans to buy off the Germanic aggressors met with scorn, further evidence of a boy tied too-tight to his mother’s apron strings and thoroughly unsuited to the martial rigors of ruling the empire.


The soldiers instead alighted upon Maximinus Thrax, a career soldier of lowly origin and reputedly colossal size. Alexander’s time was up. Panic-stricken, he could do little more than lament his fate at the imperial camp at Moguntiacum (modern Mainz). Both he and his mother were cut down in March AD 235. The Severan dynasty had ended.


2. The Senate Strikes Back? The Rise of the Gordian Dynasty

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Portrait bust of Maximinus Thrax, AD 235-238, Capitoline Museum, Rome, via Wikimedia Commons


Maximinus Thrax was not a typical emperor. Born on the Danubian fringes of the Roman Empire– hence Thrax (literally, ‘the Thracian’) – he appears to have entered the service of the Roman army and risen through the ranks. By all accounts, he was an excellent soldier, well-respected, and famously brave. In short, he was the antithesis of Alexander.


The Historia Augusta asserts that he was monstrously large ( thumbs so big he wore his wife’s bracelets as rings and strong enough to pull wagons by himself). Although this description seems unlikely, he must have been an imposing figure. Maximinus appears to have been self-conscious of his lowly origins throughout his reign. Several attempted revolts would suggest his fears were not unfounded.


The emphasis of his reign was on the military. He quashed the insurrections on the frontiers – notably displaying his bravery against the Germanic tribes. He also appears to have been responsible for attempting to fortify the region, as attested by a series of milestones discovered there.


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Silver antoninianus of Pupienus, with reverse depiction of clasped hands of imperial colleagues, AD 238; and silver antoninianus of Balbinus, with reverse depiction of clasped hands of imperial colleagues, British Museum, London


Maximinus’ reign was never secure, however. Tensions erupted in AD 238, first in North Africa. A landowner’s revolt in the city of Thysdrus (El Djem, modern Tunisia, a city famous for its spectacular Roman amphitheater), resulted in the rebels proclaiming the elderly governor of the province, Marcus Antonius Gordianus Sempronianus as emperor, and his son as his colleague. Gordians I and II would not last long. The governor of Numidia, Capelianus, was loyal to Maximinus. He marched into the city at the head of the only legion in the area. The rebels – mostly local militia – were slaughtered along with Gordian II.


Upon hearing of his son’s death, Gordian I hanged himself. However, the die had been cast. Rome’s senate had supported the Gordian revolt in Africa and was now backed into a corner. Maximinus would show no mercy. The senate elected two elderly members – Pupienus and Balbinus – to stand as emperors in Maximinus’ stead. A violent plebeian outcry at the elevation of two aristocrats also compelled the senate to nominate Gordian III (the grandson of Gordian I) as the younger colleague of Pupienus and Balbinus.


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Portrait bust of the Emperor Gordian III, photograph by Louise Laffon, 1863-1864, Victoria and Albert Museum


From the north, Maximinus marched on Rome. He entered Italy largely unopposed but soon had to halt before the gates of Aquileia. The city had been made fortified in AD 168 by Marcus Aurelius, ostensibly to protect Italy from northern barbarian incursions. Yet, now, some 70 years later, it found itself defending the senate against the Emperor.


The siege of the city dragged on, and Maximinus’ support waned in the face of this military failure. By late May 238, his soldiers, suffering from starvation and tempted by the promises of clemency from the defenders, slew Maximinus and his son. The emperor’s head was removed, placed atop a spear, and carried to Rome (an event even commemorated on certain rare coins!). Calm was not restored to the empire, however. Despite the promise of fraternity and cooperation made through the clasped-hand coinage, mistrust brewed between Pupienus and Balbinus. Discussion over a renewed military campaign spilled into violence, with the Praetorian Guard cutting down the elderly emperors, leaving the young Gordian III as sole emperor.


 3. Goths and Gods: The Reign of Emperor Decius

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Saint Reparata before the Emperor Decius, Bernardo Daddi, 1338-40, Met Museum, New York


Gordian III reigned from 238 to 244, but his youth meant that others wielded power in practice. A spate of earthquakes destroyed a number of cities across the Roman empire. At the same time, Germanic tribes and the Sassanids increased their attacks across the imperial borders. Despite early successes against the Sassanians, Gordian III appears to have died at the Battle of Misiche in 244. The role of his successor, Philip the Arab, remains somewhat suspiciously unclear. Philip’s reign was notable for the celebration of the ludi saeculares – the Secular Games – in 247, to coincide with Rome’s millennium.


Philip was killed in AD 249. He was defeated in battle by the usurper, and his successor, Gaius Messius Quintius Decius, who had the support of the formidable Danubian legions. Decius had been active in the empire, serving as a provincial administrator under both Alexander Severus and Maximinus. Decius instigated attempts to restore normality across the empire. Emblematic of this were the Baths of Decius. The Baths were constructed in Rome on the Aventine Hill in AD 252 and survived until the 16th century.


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Relief and detail of the Luodivisi Battle Sarcophagus, depicting a battle between the Romans and Goths, ca. AD 250-260, Palazzo Altemps, Rome


Decius is perhaps most infamous for the so-called Decian persecution. During this period, Christians across the empire were persecuted and martyred for their faith. The persecutions began in AD 250, following the proclamation of an edict by the new emperor, which ordered all inhabitants of the Empire to perform a sacrifice to the Roman gods and the emperor’s health. In effect this was a mass oath of loyalty to the Empire and emperor. However, the sacrifice presented an insurmountable obstacle to the monotheistic beliefs of Christians. Given that Jews were exempt, it seems unlikely that the persecution targeted the Christians deliberately. Nevertheless, it had a profoundly traumatic impact on the nascent Christian faith. Many numbers of believers died, including Pope Fabian. Others, including Cyprian the Bishop of Carthage, went into hiding. The persecutions began to die down from AD 251 but would be a recurrent feature of Roman history.


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Bronze statue identified as the emperor Trebonianus Gallus, AD 251-3, Met Museum, New York


Like many of his immediate predecessors during the crisis of the third century, Decius’ reign was characterized by both internal and external pressures. A plague had ripped across certain provinces, particularly in North Africa ( sometimes referred to as the Plague of Cyprian, named after the Bishop of Carthage). At the same time, the northern imperial frontiers were tested by increasingly more audacious barbarian armies, particularly the Goths. During Decius’ reign, the Goths, who would be so prominent in the fourth and fifth centuries, in particular, appear in the historical record.


Decius’ reign came to an end during these Gothic Wars. Accompanied by his son Herrenius Etruscus and the general Trebonanius Gallus, resplendent in heroic nude above, Decius faced the Gothic invaders at the Battle of Abritus (near Razgad in modern Bulgaria) in AD 251. The Roman army came unstuck in the marshy environs of Abritus and the emperor and his son were cut down in battle. Decius was the first Roman emperor to fall in battle against a foreign enemy. He was replaced by Trebonianus Gallus.


4. Prisoner of the Persians: Emperor Valerian

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Sardonyx cameo showing the Emperor Valerian and Shapur I, late 3rd century, Met Museum, New York


Imperial control remained elusive following Decius’ death. The years 251 to 253 featured three emperors. The last, Aemilian, ruled for just a few short months in the summer of 253. He was replaced by Valerian I, who appeared to be something of a throwback. He was an emperor from a traditional senatorial family, with a career in the imperial administration, including as Censor after the censorship’s revival by Decius in AD 251.


Upon taking control of the empire, Valerian moved quickly to consolidate authority, naming his son Gallienus as his heir. However, Valerian’s Reign was also the moment at which the Roman Empire’s military crises appear to have approached their apogee. On the Northern European frontiers, the Goths kept rampaging while Sassanid aggression continued in the east. The pressures on the empire saw a revival in Christian persecutions, as they were again commanded to perform sacrifices to the Roman gods in AD 257. In the Valerian persecution, many prominent Christians, who refused to apostatize, were martyred for their faith, including Cyprian in AD 258.


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The humiliation of the emperor Valerian by the Persian king Sapor, Hans Holbein the Elder, 1521, Kunstmuseum, Basel

However, Valerian’s historical reputation was cemented by events in the east. Father and son divided their forces. Gallienus headed charged with defending the Empire from the Goths, whilst his father marched East to confront the Sassanids. Initially, Valerian enjoyed some successes. He retook the cosmopolitan city of Antioch and restored Roman order to the province of Syria by AD 257. However, by AD 259 the situation had deteriorated. Valerian had marched further east to the city of Edessa, but an outbreak of plague there weakened the emperor’s forces as the town was besieged by the Persians.


In the spring of AD 260, the two armies took to the field. Led by Shapur I, the Sassanid Shahanshah (King of Kings), the Sasanians utterly annihilated the Roman forces. In one of the most famous events of the crisis of the third century, Valerian was captured and condemned to a shameful life as a prisoner of the Sassanians. The later Christian author, Lactantius, records Valerian living out his days serving as the King’s footstool. The less partisan writer, Aurelius Victor, records the emperor being kept in a cage. Valerian’s submission was immortalized in a monumental rock-carving at Naqsh-e Rosta in northern Iran.


5. Breakaway: Gallienus, Postumus and the Gallic Empire

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Portrait of the Emperor Gallienus, AD 261, Musée du Louvre


Although the crisis of the third century is typically presented as a period of pronounced political instability, it is notable that Valerian and Gallienus respectively reigned for a considerable amount of time.


However, in the quarter of a century after Decius’s death in AD 251, the empire almost collapsed as a political structure, with the eight-year reign of Gallienus from AD 260 to 268, military pressures, and the fragmentation of the empire in places. Ashis father was campaigning in the East, Gallienus was fighting on the Northern borders of the empire, near the Rhine and the Danube. Whilst campaigning there, one of the governors in the Pannonian provinces, a certain Ingennus, declared himself emperor. His usurpation was short-lived but an ominous sign of things to come. Gallienus marched across the Balkans with all haste and defeated Ingennus.


The emperor fought the pretender. However, the power vacuum left in the Germanic region encouraged an invasion by tribes across the limes, spreading terror across the western European provinces. The invaders even reached as far as southern Spain, where they sacked the city of Tarraco (modern Tarrangona). The pattern had been set for the coming years. This was to be the most turbulent period of the crisis of the third century.


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Gold aureus of Postumus with helmeted obverse portrait and reverse depiction of Hercules of Deuso, AD 260-269, British Museum


The collapse of Roman authority was felt most keenly in Gaul. Here, as the frontiers failed in Europe, the governor of Germania – Marcus Cassianus Latinius Postumus – defeated a raiding party. Rather than surrender the booty he had won to Silvanus, the man overseeing Saloninus (Gallienus’ son, and co-emperor), Postumus instead distributed it to his soldiers. In a pattern common throughout the history of the Roman Empire, the grateful soldiers promptly declared Postumus emperor. However, where previous up-start emperors may have marched on Rome, Postumus appears to have lacked the resources or even the inclination. Instead, he established a separate state, the so-called Gallic Empire, which lasted from AD 260 to 274.


The nature of Postumus’ new empire is hard to discern (the already scarce sources give it short shrift for these turbulent decades). Nevertheless, it enjoyed some success spreading from Gaul into Britain and northern Spain. Moreover, as the coinage above makes clear, culturally, the Gallic Empire was wholly Roman.


6. Aurelian: Reconquest of the Roman Empire

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Queen Zenobia Addressing Her Soldiers, Giovanni Battista Tiepolo, 1725-30, National Gallery of Art, Washington


The secession of the Gallic Empire during Gallienus’ reign was one of a myriad of problems facing his imperial successors. At the same time, it was becoming clear that the Roman empire was faltering in the east, too, especially at Palmyra, the wealthy trading city in Syria. After the Palmyrene leader, Odaenathus, was declared king, ostensibly to help the city defend itself against the Sassanians, it became clear that a new eastern state was emerging, to mirror the western imperial break-up. Odaenathus was assassinated in AD 267, and replaced by his ten-year-old son, Valballathus, with the queen, Zenobia, serving as regent.


Zenobia emerges from this period as one of the strongest and most intriguing personalities in later Roman history. Her period of influence straddles the reign of two Roman emperors: Claudius II Gothicus (AD 268-270) and Aurelian (AD 270-275). The initial strikes back against the Sassanians were ostensibly done under Roman authority. Still, the territorial gains made, including in Egypt, and the increasing grandiosity with which Zenobia had her son presented, escalated tensions and war was inevitable upon Valballathus taking the title Augustus in AD 271.


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A silver Antoninianus of Aurelian, with reverse depiction of the god Sol Invictus and defeated enemies, 270-275, Digital Coin Cabinet of Eichstätt University


Aurelian’s arrival in the east in AD 272 led to the rapid collapse of the Palmyrene empire amidst a series of anecdotes and historical snippets. Two battles were fought, at Immae near Antioch and then Emesa, as the emperor pushed on for Palmyra. A siege of Palmyra followed, with the Romans unable to breach the walls. As the situation deteriorated for the defenders, Zenobia attempted to escape. She was seeking out Persian support when she was captured near the Euphrates and brought before the emperor.


The city itself was spared destruction following its surrender, as was, reputedly, Zenobia. However a second attempted uprising by the Palmyrenes in AD 273, quashed again by Aurelian, led to the evaporation of the emperor’s patience. The city was razed, and its most precious treasures taken to adorn Aurelian’s Temple of Sol in Rome, the sun deity to whom he was famously devoted.


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Roman Antiquities, View of the Aurelian Walls, Giovanni Battista Piranesi, ca. 1750, Victoria and Albert Museum, London


Following the Palmyrene Empire’s defeat, Aurelian’s focus shifted west once more. Here there were two issues to resolve: the Gallic Empire and the weakness of Italy itself, demonstrated by the frequent Germanic incursions of the previous decades. To strengthen the empire’s capital, Aurelian oversaw the construction of a colossal defensive wall around Rome, which stands tall and imposing to this day.


The Aurelian Walls protected the city but served as a reminder of the Roman rule’s fallibility. Where once its citizens might have bragged that she needed no walls, now they lived in their shadow. To the north, the Gallic Empire was crumbling, crippled by succession contests in the aftermath of Postumus’ death. The elevation of Gaius Tetricus in AD 273 led to the Gallic Empire’s collapse. Although he managed to negotiate his own surrender, his army was routed by the Romans. The double triumph that followed thereafter was a temporary return to halcyon days of imperial glory. Zenobia and Tetricus and his son paraded through the imperial capital as a testament to the empire’s enduring strength.


7. The Crisis of the Third Century Ends? Probus, Diocletian, and the Imperial Order Remade

Gold aureus of Probus, with reverse depiction of winged victory,  AD 276-82, British Museum


Traditional narratives frame the reign of Aurelian as a turning point in the crisis of the third century; his victories in the east and west, his reunification of the empire, and his fortification of his capital testify to the reassertion of Roman power. However, there is little in the reigns of his immediate successors, Tacitus (a fan, not a descendant, of the first century historian) and Florianus, that the empire was on the route to definitive recovery. Indeed, the hapless Florianus appears to have been emperor for less than 100 days!


The empire then passed to the control of Probus. He appears to have spent almost the entirety of his six-year reign at war, with the borders once more proving particularly porous. He evidently enjoyed some successes against Rome’s enemies. He took the titles Gothicus Maximus and Germanicus Maximus in AD 279 and celebrated a triumph in AD 281. However, he was killed in AD 282 whilst marching east.


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Fragment of a togate statue of the emperor Diocletian, ca. AD 295-300, J. P. Getty Museum


The circumstances surrounding Probus’ death remain unclear. His Praetorian Prefect, Marcus Aurelius Carus, appears either an unwilling beneficiary or active conspirator. Carus, from southern Gaul, attempted to placate the political instability by nominating his sons, Carinus and Numerianus as his heirs.


Carus’ reign was cut short by divine intervention when lightning struck him on a campaign in the east in AD 283. Numerianus, on campaign with his father, was slain by the praetorian prefect, Aper, who seemingly lacked the courage to follow up his violence, and did not declare himself emperor. Aper was, in turn, struck down, and the soldiers of the east gathered to elect a suitable leader.


They settled on a junior officer, Diocles, whose background is largely unknown. Acclaimed in AD 284, Diocles took a new name: Marcus Aurelius Gaius Valerius Diocletianus. Carinus himself would be betrayed to Diocletian. The empire returned to the control of one man. Diocletian, however, had no interest in suffering the same fate as many of his predecessors and ushered in a period of profound change. With Diocletian the curtain was brought down on the crisis of the third century, and imperial history passed from the Principate to the Dominate.

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By Kieren JohnsPhD Classics & Ancient HistoryKieren is a UK-based independent researcher with a PhD in Classics and Ancient History. His thesis explore the representation of imperial status during the reigns of the Severan emperors. He is passionate about sharing his interest in the ancient world. He is currently writing his first book.