What Was the Crisis of the Third Century?

The Crisis of the Third Century was a turbulent period characterized by military, economic, and political challenges that brought the Roman Empire to the brink of collapse.

Feb 15, 2023By Vedran Bileta, MA in Late Antique, Byzantine, and Early Modern History, BA in History

what was the crisis of the third century


The so-called Crisis of the Third Century was a period of chaos, anarchy and economic instability in the Roman Empire. In less than a hundred years, no less than 24 emperors exchanged on the throne, a stark contrast when compared with 26 emperors who ruled from the time of Augustus to Septimius Severus, a period of over 250 years. It was an era of soldier emperors, backed by their legions, and the recurring civil wars that brought the Empire to the brink. In one moment, the Roman Empire split into three separate parts. Only the efforts of emperor Aurelian saved the Empire.


The Crisis of the Third Century also saw increased pressure on the imperial borders, with enemy forces advancing into the Roman territory. No wonder many emperors lost their life on the battlefield or were assassinated at the hands of their own men. The Roman Empire, however, managed to survive. The turmoil ended with the accession of emperor Diocletian, who instituted a new political system – the Tetrarchy or the “rule of four” – stabilizing the Empire and bolstering its power and strength. 


The Crisis of the Third Century Started with An Assassination

alexander severus gold coin
Gold coin of Alexander Severus, and silver coin of Maximinus Thrax, 220 and 235 AD, The British Museum


At the onset of the Crisis of the Third Century, the Roman Empire enjoyed a period of stability. The throne was occupied by the members of the powerful Severian dynasty, founded by emperor Septimius Severus. Ironically, Severus was the one who strengthened the importance of the army, which would play a major role in the century of turmoil. The soldiers were powerful supporters, but their increased political role led to the death of soldier emperor Caracalla and his erratic successor Elagabalus.


Thus, when the last Severan emperor, young Alexander Severus, suffered a heavy military defeat, the army decided to get rid of the inexperienced emperor, assassinating hapless Alexander in 235 AD. In his place, the legions elected a career soldier of low origin, Maximinus Thrax. The Severan dynasty has ended.

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The Soldier Emperors Rarely Kept the Throne for Long

ludovisi battle sarcophagus
Ludovisi Battle sarcophagus with Romans fighting the barbarians, mid-3rd century CE, Museo Nazionale, Rome


Maximinus Thrax’s brief reign began and ended in blood. The emperor had the support of the army but not of the Senate. Unable to pay the troops, Maximinus was killed by his own men during the Siege of Aquileia in 238. By this time, several men laid claim to purple in different parts of the Roman Empire. To make matters worse, the Roman enemies, the Germanic tribes and the Sassanians, exploited the situation, invading the imperial territory. Some emperors were more successful in holding the throne. They even managed to stabilize the Empire, albeit briefly.


However, they perished on the battlefield, and the civil war ensued. Emperor Decius was the first Roman emperor to die in a battle against a foreign enemy. It got worse. The Roman Empire was badly humiliated after emperor Valerian suffered a heavy defeat during his failed Persian campaign in 260 and was taken captive. Besides the military losses, the deadly plague struck the Empire, ravaging its lands and killing millions, especially in the large cities. 


The Roman Empire Almost Collapsed

roman empire crisis of the third century
The Roman Empire during the Crisis of the Third Century.


The reign of Valerian’s son Gallienus was marked by an event unprecedented in Roman history. Faced with the emperor’s absence and the Germanic attacks over the Rhine, the army of Gaul chose Postumus as their emperor. He also got the backing of Spain and Gaul. Around the same time, the army in East supported the king of Palmyra, Odaenathus, and after his death, stood by his daughter, the powerful and ambitious Queen Zenobia. The Roman Empire was now fragmented into three parts. Italy, the Balkans and North Africa still recognized emperor Gallienus. However, he had to face the Gallic Empire in the West and the Palmyrene Empire in the East (which controlled the wealthy and crucial province of Egypt). The Roman Empire was about to collapse.


Emperor Aurelian Saved the Empire

bust of roman emperor aurelian
Bust of a Roman emperor, probably Aurelian, ca. 275 AD, Museo di Santa Giulia, Brescia


Unsurprisingly, Gallienus, too, perished on the battlefield and was succeeded by emperor Claudius II Gothicus. Claudius was a successful military commander, and under his command, the Roman legions scored a major victory over the invading Gothic tribes, stabilizing the Danubian frontier. Claudius, however, died soon after the battle, in 270, leaving the task of saving the Roman Empire to his heir, emperor Aurelian.


With a huge effort, Aurelian defeated the armies of Zenobia, bringing the rebellious queen back in chains to Rome. Then, the emperor moved his legions westwards, ending the Gallic Empire for good. It was a momentous triumph, and Aurelian was rightly awarded the title “Restitutor Orbis” – Restorer of the World. The ambitious emperor now prepared to invade Persia. However, Aurelian was assassinated by his own troops en route to the East in 275.


Diocletian Ended the Crisis and Established the Tetrarchy

tetrarchs four emperors equals carole raddato
The Tetrarchs: Four Emperors Depicted as Equals photographed by Carole Raddato, 300 A.D.,  in St. Mark’s Square Venice


Aurelian’s sudden death led to another civil war and destabilized the Empire he fought so hard for. The barbarian attacks also continued, as well as the war with the Sassanid Empire. The reign of Probus briefly stabilized the situation, but the emperor was killed while marching to the Eastern front. Finally, in 284, after another civil war, emperor Diocletian ascended the throne. Aware that one man alone could not rule the vast territory, Diocletian first chose his colleague Maximian as the co-emperor.


Then, to further bolster the Roman Empire’s stability and secure its unity, the two senior emperors (augusti) chose two juniors (caesares), establishing the Tetrarchy – the rule of four. With this, the Third Century Crisis came to an end, ushering in the late Roman Empire, a period also known as a Dominate. Diocletian’s reforms continued even after the fall of Tetrarchy, during the sole reign of emperor Constantine the Great


The efforts of emperors Aurelian, Diocletian and Constantine, secured the survival of the Roman Empire more than a millennium, until the fall of medieval Roman state (also known as the Byzantine Empire) in 1453.

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By Vedran BiletaMA in Late Antique, Byzantine, and Early Modern History, BA in HistoryVedran is a doctoral researcher, based in Budapest. His main interest is Ancient History, in particular the Late Roman period. When not spending time with the military elites of the Late Roman West, he is sharing his passion for history with those willing to listen. In his free time, Vedran is wargaming and discussing Star Trek.