Introduction: Emperor Aurelian and the Crisis of the Third Century

The Crisis of the Third Century (235-285 CE) was the combination of administrative incompetence, foreign invasions, and the fracturing of the Roman Empire into three self-governing states which nearly collapsed the Roman Empire. However, the empire was able to recover and survive for nearly another 1,200 years, in large part due to Emperor Lucius Domitius Aurelianus. By the end of Aurelian’s five-year reign (270-275), he almost completely stabilized the empire. Aurelian addressed the Crisis of the Third Century in three main ways: through his pragmatic and revolutionary administrative policies, his military prowess in handling attacks from Germanic tribes, and his reconquering of the Palmyrene and Gallic Empires. These aspects of Aurelian’s rule were vital to restoring the Roman Empire and nearly ending the Crisis of the Third Century. 

The Role of the Emperor and the State of the Roman Empire before Aurelian

Like nearly all of the emperors of the third century, Aurelian belonged to a new class of skilled military commanders that had few ties to the Roman Senate. Instead, these emperors rose to power through their military achievements. Aurelian was born on September 9, 214 CE to a peasant family just south of the Danube and joined the army when he was around 20. A career soldier, Aurelian became a senior officer in the central imperial field army by 268, and in 270 he was elevated to the position of emperor. He set himself apart from previous emperors of the third century in several important ways that ultimately enabled him to rescue the Roman Empire. 

The world that Aurelian knew was dominated by war-focused emperors which stretched the resources of the Roman Empire to its limit. For one, the position of Roman emperor was ill-defined and hard to keep. There was no set method of succession. To legitimize their rule, prospecting emperors declared themselves the successor of Augustus, which indirectly required emperors to have strong military ties. However, this could lead to multiple contenders fighting for the role. Additionally, the military took on an important role in the selection process, even surpassing that of the Roman Senate. As early as the reign of Tiberius, emperors were already dating their reigns from when the army proclaimed them emperor rather than the senate. As a result, emperors began to prioritize their military victories over long-term planning or other facets of the role of emperor. This in turn led to more violence and civil war. 

The Roman Emperor also became more reliant on military leaders. This caused rivalries between the military elite and the sitting emperor that resulted in assassinations and political coups. Moreover, the pressure of foreign invasions placed impossible demands on the Roman Emperor, and the price of failure was high. The emperor’s presence was demanded at every front, but he could only be in one place at a time. If he did not arrive at the front lines, the general stationed there might attempt to usurp power and march on Rome. During the Crisis of the Third Century, over 60 individuals laid claim to the position of emperor in just a 50-year span, and only one or two died outside of combat.

The Roman Senate also weakened because of increasingly military-oriented emperors. Although individual senators could still be powerful within the entourage of the emperor, the traditional role of the senate diminished. Increasingly, decisions were made far from Rome while the emperor was away on military campaigns. Another reason for the senate’s lack of influence was the exclusion of senators from military command. While the imperial administration opened up to the equestrian class, true power remained with high-ranking army officials who maintained little connection to the senate. The senators of Rome who traditionally oversaw the administrative and economic wellbeing of the empire lost much of their political power.

Because Rome’s senate started losing influence, the empire became decentralized. Rome moved from a physical place to, in the words of contemporary historian Herodian, “wherever the emperor happened to be” after the late second century. This was typically near branches of the imperial mint, which became de facto regional “capitals.” Usurpers used this decentralization as an easy way to gain power by claiming these capital cities as power bases. In this way, usurpers could take control of one part of the empire without taking control of the entire empire, which would allow them to stay in power longer—further lending credence to their legitimacy. The third century therefore became a period rife with civil war, as emperors had to deal with competition from within the empire.

War also became more expensive during the third century. This was partially due to the reformation of the army in response to new threats to the empire. The Roman army was originally designed for powerful strikes at specific targets, but now in the third century, this tactic was no longer useful. Smaller military detachments replaced old Roman legions, while rapid and mobile cavalry increased. Furthermore, war used to be mostly conducted outside of the empire, which allowed plunder retrieved from other states to pay for campaigns, resulting in a net gain in profit for the Roman empire. However, in the third century, battles were increasingly being fought on Roman territory so any plunder retrieved would have been originally taken from Roman provinces. This meant that the imperial government was effectively taking money back from itself, breaking even at best, but almost always incurring a loss due to military costs. Furthermore, more resources were allocated to paying military personnel. The military budget increased when Commodus, Marcus Aurelius’ successor, and Pertinax were murdered by the Praetorian Guard in short succession in 192. After a power struggle, Septimius Severus became the next emperor. According to contemporary historian Cassius Dio, he pledged to “enrich the soldiers and scorn the rest” in order to secure the military’s support.  To do this, Septimius himself and his son Caracalla increased both the base pay of soldiers and special occasion cash bonuses. 

With the rising cost of war, the empire suffered from the senate’s inability to make long-lasting economic plans and to reform the inefficient tax system. Because the wealthy were able to avoid taxes through bribes and loopholes, most taxes fell on those who could not afford them. Therefore, to finance Rome’s expenses, the government relied on a variety of unpopular and short-term solutions. One of these was confiscation, where supporters of the losing side in the numerous civil wars of the time would have their property taken. The empire would also commandeer resources from its citizens to feed and billet its army. The last solution was to begin taxing “in kind,” or taxing in terms of goods and services to bypass the rapidly decreasing value of the currency. 

The decreasing value of the currency was caused by the practice of debasement of Rome’s coinage. This practice was initiated by Emperor Nero (54-68) and was used infrequently by successive emperors, affecting silver coinage the most. However, from the reign of Caracalla in 198 onward, Roman emperors adopted a large-scale policy of debasement. For example, Caracalla lowered the gold coin’s weight to 50 to the pound, meaning that 50 gold coins weighed one pound, and lowered the value of silver coinage too. In 215, he introduced a new silver coin called the antoninianus, which was tariffed at the artificially high price of two denarii. In 238, this coin became the main silver coin, but it remained heavily debased. Under Gallienus, the coin was just 1.5% silver and was otherwise made up of less valued metals. All of these factors led to the collapse of Rome’s currency and extreme inflation by the end of the third century. For example, Diocletian’s edict on maximum prices in 301 shows that the price of wheat was two hundred times more than its price during the second century. Ironically, this debasement affected the government the most, since the daily lives of Romans were not very monetized. However, taxation and administrative costs like paying officials and the army became much harder. These factors led to the erosion of Rome’s administration and to political instability.

Aurelian’s Solutions to Rome’s Administrative Problems

While other emperors focused almost exclusively on military matters, Aurelian was unique in his attempts to fix various Roman administrative systems, especially the problems with Rome’s depreciating currency and the urban food dole—the distribution of free food to poor Roman citizens. In order to resolve these problems, Aurelian had to first curb internal corruption in his own administration. 

After a close Germanic invasion in 271 CE, the Roman mint began issuing extremely debased coinage. The corruption, so extreme that it was probably a form of sedition, was spearheaded by Felicissimus, who was Rome’s chief finance minister. After inciting the mint workers to revolt, he was immediately killed. However, his death did not end the turmoil that was to come. Tensions were already high in Rome, especially due to the Germanic scare, but also because the Palmyrene Empire—a semi-independent state in the process of seceding from the Roman Empire—was disrupting the grain supply from Egypt. The situation quickly turned into a deadly riot in Rome, which was further incited by a number of senators who disliked Aurelian. By the time Aurelian returned to Rome, the mob and urban cohorts had already fought a bloody battle. Aurelian restored order and executed those in charge, “even [killing] some senators of noble birth,” according to the author of the Historia Augusta. After closing down the Roman mint, Aurelian hired a new and competent finance minister named Gaius Valarius Sabinus, who was likely responsible for carrying out many of Aurelian’s monetary reforms. 

In response to the riots, Aurelian’s administration initiated a minor coinage reform. There was a slight improvement to the weight of the silver coin and in the control and quality of minting. Finally, Aurelian moved the center of minting to Milan and opened two new mints in the Balkans before he left to fight Germanic tribes. In this way, Aurelian took back control of the empire’s mints and paved the way for more lasting change in the restoration of Roman coinage.

Aurelian then took stronger measures to reform the coinage system in the last two years of his reign. In late 273, Aurelian prioritized reforming the currency. He recalled old coinage and replaced it with new coinage that was heavier in weight and more controlled. The only literary evidence for this comes in Zosimus’ New History,  however there are substantial archaeological findings for the reform. Before, coins were minted between 86 and 98 to the pound, but they were now minted between 81 and 90 to the pound. A modern analysis of the silver content in recovered coins jumps from 3.49% before the reform to 4.1% after, which likely signified a percentage of 5% silver when the post-reform coins were still in mint condition. Furthermore, gold coins that used to be minted at 60 to the pound were now at 50 to the pound, restoring them to values from the time of Caracalla. Finally, Aurelian reintroduced bronze coinage after the silver reform since the old debased silver had previously filled the role of base-metal currency.

Aurelian also sought to secure and standardize the mint system. Traditionally, minting was concentrated in Rome. Coins that paid troops and spread the emperor’s legitimacy had to be transported long distances. With the rising threats of Germanic invasion and mutiny though, it became better to have mints closer to the front lines. In 253, Emperors Valerian and Gallienus inherited the mints at Alexandria, Rome, Viminacium, and Antioch. Eight different mints were used in total during their reigns, with only four or five ever used at once. The new mints used were at Trier, Milan, Siscia, and one either in Cyzicus or Ephesus. Trier fell to a usurper in 260, so Claudius, successor to Gallienus, only inherited Rome, Milan, Siscia, Antioch, and the mint at either Cyzicus or Ephesus. 

In contrast to past emperors, Aurelian used a total of twelve mints over the course of his reign, though no more than eight were ever in use at a time. Because foreign invasions in the Levant took Antioch and Alexandria in 270, Aurelian started with only four mints: Rome, Milan, Siscia, and Cyzicus/Ephesus. The latter two were the first mints to work for Aurelian after briefly serving Quintillus, and Siscia initially was his most important mint. By the end of his reign, the mint at Siscia was the second most important, minting a quarter of all his coins. Milan eventually became Aurelian’s most important mint, until 274 when it was transferred to Ticinum. After the Roman mint was closed because of the Rome riots, it reopened in 273 at a reduced level. Aurelian recaptured the mint at Alexandria in 272 and the mint at Antioch in 273 as well. After reuniting the empire, Aurelian gained control of Trier and soon closed it. Aurelian also set up five new mints during his reign, one at Serdica and one at Byzantium in 271, one at Tripolis in 273, and one at Ticinum and one at Lyon in 274. Even though Aurelian expanded the number of mints, he did not sacrifice quality for quantity. Aurelian exercised much tighter control over his mints than his predecessors, ensuring the standardization of weight, silver content, and issues. In fact, the uniformity of his coins has made it challenging for historians trying to determine which mints his coins came from.

Aurelian also reformed the urban food dole. It had been a long time since the city of Rome was able to fully satisfy its food needs solely through Italian farming only. Instead, Rome relied heavily on imported grain from Egypt. Some of this grain was distributed for free in Rome to poorer land-owning men. The rest was milled and sold to bakers who would sell their bread at highly controlled prices. Aurelian increased the frequency of the food dole to now be given every day, and added two free pounds of bread. He also used state money to subsidize bakers to sell their price-controlled bread with an extra ounce. Furthermore, he increased the distribution of oil, salt, and pork, which had not been common before his reign. Lastly, he sold government-owned wine at a low price. These public works and services were mainly to prevent future Roman riots, because Aurelian believed that Rome still mattered symbolically and another Roman riot would jeopardize his rule.

Although Aurelian’s quality-of-life reforms were highly successful, his monetary reforms were only somewhat effective. The new coinage was less useful since it was worth too much, while old debased coins and counterfeits could still be used for everyday small change. Even if financial stability was not restored though, there was not much more Aurelian could have done considering the many military matters he had to deal with. Moreover, the monetary reforms Aurelian accomplished were still impressive. Coin issues were tightly controlled by Sabinus, who was highly capable and worked exactly as Aurelian wanted him to. The quality of coins was highly standardized and the mints themselves heavily regulated.

Foreign Invasions into Roman Territory during the Crisis of the Third Century

Aurelian came to power when the Roman Empire was territorially overstretched and militarily weak. In the second half of the second century CE, Rome increasingly became the prey and not the predator of its neighbors. This was in part due to Rome’s earlier successes in the East which overextended Roman rule. Another contemporary development that weakened Rome’s command structure was the involvement of the military in choosing the next emperor. When Commodus was murdered and Pertinax a few months later, the Praetorian Guard began to auction off the title of emperor. The Roman armies of Britain, the Danube, and the East followed suit and promoted their own leaders as well. Septimius Severus, reigning from 193 to 211, was the Danubian candidate and winner. Septimius and later Caracalla were able to defeat Rome’s old enemy in the east, the Parthians, but vastly overextended by annexing Orshoene and Mesopotamia. Within a decade of Caracalla’s campaign, the Parthian Empire had rebirthed into the far more formidable Sassanids. The new threat was an intolerable strain on Roman forces in the east, with Shapur I leading the charge with large invasions in 252 and 260. 

Additionally, on the northern front, new invaders posed a fresh set of challenges for Rome’s armies. At the start of the third century, large groups of Germanic peoples migrated and pressed on Rome’s northern borders from the Rhine to the Danube. The invasions of the Germanic tribes intensified in the third century, targeting wealthy Roman provinces and undefended towns. One such group was the Goths, who arrived in Southern Ukraine no later than 230. They occupied a significant amount of territory north of the lower Danube, and by 240 were in direct conflict with the Roman Empire. In 250, the Goths launched a full-scale invasion of the Balkan provinces, destroying Roman defenses there. Eastern Goths also launched naval raids on the coast of the Aegean and Black Sea. Between the Goths and the province of Dacia were the Carpi and to the west were the Vandals and other neighboring tribes. In 213, the Almanni appeared in what is now Bavaria, while the Franks formed in the lower Rhine in the 250s.

These foreign invasions contributed to internal unrest and set off many of the subsequent civil wars. In just six years, five claimants to the position of emperor came and went in the Danube alone, in the process opening up the empire’s borders to further attacks from foreigners. After a successful Danubian campaign in 247, Emperor Philip left for Rome, leaving the area open for new Gothic raids again. In 249, the Danubian army elevated Pacatianus to emperor. Philip sent his general Decius to deal with the uprising but Pacatianus was lynched before Decius even arrived. However, Decius was pronounced emperor in turn and so he marched on Rome, defeating Philip. With nothing in their way, the Goths then returned to invade and the Carpi started attacking Dacia. Decius returned to defend the Balkans but suffered a decisive defeat in 250. A year later, he was ambushed and killed. In another case, in 253, Aemilianus intercepted a group of Goths in the lower Danube and was made emperor on the spot. Gallus, the standing emperor at Rome, marched on Aemilianus, while reinforcements from his general Valerian would arrive later. Before Valerian arrived though, Gallus had been killed and Aemilianus assassinated. Valerian was then made emperor and fortified important parts of the Danube that had been open for attacks. However, the Rhine was still under siege from the Alamanni, while in the east the Persians had taken Syria. These examples demonstrate the constant military pressures faced by Rome’s armies and its standing emperor.

The Roman Empire eventually was forced to rely on the help of non-Romans to defend its eastern territories. The eastern frontier had no defined boundary outside of the Syrian Desert, which contained predictable trade routes. One major hub of trade was the city of Palmyra, whose growth and economy was based on this commerce. Although the city had been relatively autonomous even after being formally incorporated into the Roman Empire, Palmyrene troops formed an important part of Rome’s defense in the east. Palmyra worked with Rome because they feared that the alternative, Persian control over their trade routes, would be far worse.

When Roman forces failed to protect the eastern front though, the Palmyrene armies stepped in, further decentralizing the empire. After Gordian had been defeated in Persia, Philip was forced to sue for peace with Shapur I. However, when Philip left to deal with the aforementioned Decius, Shapur attacked; by 251, Shapur completely removed any Roman influence in the Euphrates and Mesopotamia. When Valerian returned in 260 to fight Shapur, he was defeated and taken prisoner. Shapur unleashed devastation as soon as Valerian was taken captive, overrunning Syria and attacking Cilicia and Cappadocia, but eventually returned east to regroup. These victories are proclaimed at The Great Inscription of Shapur I. On his retreat, however, he was blocked by Odenathus of Palmyra. Odenathus was part of the Palmyrene elite who had been granted Roman citizenship starting at the beginning of the third century. He rose to power by his own means and was made an honorary member of the Roman Senate for his work for the Roman Empire. Odenathus responded to Shapur’s invasions in 252 and 253, and by 257 or 258 Odenathus even received an honorary consular title for dealing with Shapur’s attacks. During Shapur’s invasion of 260, Odenathus was once again compelled to fight the Persians because of the threat the Sassanids posed to Palmyra’s trade. Odenathus attacked tired Persian forces as they marched to the Euphrates and drove them out of Roman territory. 

The announcement of Valerian’s capture caused many other insurrections and invasions to take place across the empire. Aurelian would end up having to deal with the resulting turmoil during his times as military commander and emperor. Gallienus, the new emperor at Rome and son of Valerian, was barely able to hold them off, but never fully controlled the empire after that. To ease the load, he gave Odenathus nearly full control over the eastern provinces. In 262, Odenathus took northern Mesopotamia and Nisibis back from the Persians, and in 266 or 267, Odenathus almost took Ctesiphon, the capital of Persia. By 267, Odenathus had become something between a powerful subject, independent king, and rival emperor, contributing to the empire’s instability. Nevertheless, he was smart enough not to boast about his achievements and provoke the true Roman emperor. 

The Rhine frontier became overrun as well during this time. The Alamanni hoped to take advantage of the political instability and breached defenses, terrorizing the area that is now Baden-Wurttemberg. Gallienus arrived in the mid 250s to deal with this threat and raised his eldest son, Valerian II, to remain as his figurehead along the Danube. This was to prevent potential uprisings in his absence. In 257, Gallienus returned to find invaders plundering northern Gaul. He set up his headquarters at the mint at Trier and used Cologne as a base to secure numerous military victories while he restored the frontier. Valerian II died in 258, but Gallienus was unfazed and made another of his sons, Saloninus, take his place. However, the Alamanni and Jugunthi were able to take the Baden-Wurttemberg area and crossed the Danube. The Jugunthi pressed down through Italy, even reaching Ravenna. Gallienus was able to stop them at Milan, but could not destroy them so they retreated with loot and captives. Meanwhile, the middle Danube, eastern provinces, and Macedonia revolted, while the Franks restarted their invasion into Gaul. Ammianus Marcellinus gives the name of the Macedonian usurper as Valens. One Frankish army penetrated deep into Spain and sacked Tarragona, reaching Gibraltar.

In late summer of 267, Gallienus received news of a massive Gothic invasion of the Balkans and Asia Minor. Gallienus left with Aurelian in accompaniment. This invasion had started in 253 when the Goths focused on Asia Minor. One of the many casualties was the destruction of the temple of Artemis at Ephesus, one of the seven wonders of the ancient world. An offshoot of the Goths, the Heruli, launched an attack down the shore of the Black Sea, taking Byzantium, before heading through the Dardanelles and plundering Greek towns. There they were challenged by a Greek militia headed by the historian Dexipus, and then forced up through Boeotia where they encountered a Roman force commanded by one of Gallienus’ generals. They were unable to completely stop the Heruli, but they drove them toward Gallienus. In the spring of 268, in the valley of Nessos, Gallienus defeated the Heruli and came to an agreement with them, granting them safe passage out of the empire. No doubt Aurelian played an important part in this victory against the invaders, which was to foreshadow his future achievements.

Aurelian’s Defenses against Foreign Invasions

Aurelian continued to add to his military achievements while he was a commander under Emperor Claudius by winning a series of decisive victories over invading Germanic tribes. These victories stabilized Rome’s borders more than ever before in the third century. When Claudius, successor to Gallienus, traveled to Rome to assume consulship for the new year, he inadvertently allowed the Alamanni and Jugunthi to strike again. They marched all the way down to Northern Italy, where Claudius defeated them in 269 CE at Lake Garda. The Heruli also decided to break their truce with the Romans and allied themselves with the Goths to form an unprecedented force. They attacked Moesia and Thrace and sailed through the Dardanelles, attacking Greek shores. Claudius, still busy, sent Aurelian to deal with the situation. 

During this phase of his military career, Aurelian was already demonstrating his exceptional military leadership. When Claudius arrived at Aurelian’s aid sooner than expected, the Goths moved to ravage northeast Macedonia instead. Aurelian managed to catch up with them there and killed many with his signature Dalmatian cavalry, driving them into Upper Moesia where Claudius lay waiting.  Although Claudius ambushed them, the majority of Goths managed to escape and continued to present a large threat. Aurelian’s Dalmatian cavalry harassed the retreating Goths for the rest of the summer and autumn. When the Goth’s provisions were desperately low, Aurelian attacked and slaughtered much of their force, sending them to Thrace. In the Great Balkan Range, the Goths were surrounded and trapped for the winter. However, the Roman forces, including Claudius, became overeager, allowing the Goths to make a last resort to break out. The Goths defeated many Romans and only Aurelian’s timely intervention with the Dalmatian cavalry prevented a complete disaster. The Goths continued marching through spring, still low on supplies and now ravaged by a plague. The plague spread to the Romans and even Claudius himself, leaving Aurelian fully in charge of taking Thrace and lower Moesia back from the Goths. Aurelian split them up into more manageable bands, recovered their loot, and recruited captives into the army and reserve militia. By summer, Aurelian was finished with the Goths, and in August, Claudius died from the plague. The Gothic wars endured, however, and Thrace was still threatened. Coastal raids were still frequent, and the countryside remained in danger. Nevertheless, these victories demonstrated Aurelian’s military prowess in defending against Germanic invasions even before his reign as emperor. 

After Claudius’ death, Aurelian used his military reputation and diplomacy to become emperor. Quintillus had been elevated to emperor by the senate, yet the Danubian army supported Aurelian. Thus, Quintillus mustered his army at Aquileia, anticipating Aurelian’s attack. However, as recorded by Zosimus, Quintillus became fearful of losing to Aurelian and committed suicide, making Aurelian the undisputed emperor. In early November, Aurelian entered Aquileia and showed mercy to Quintillus’ supporters, helping his image. Aurelian also deified Claudius during this time, both as a sincere act of homage but also to associate himself with his popular predecessor. 

After becoming emperor, Aurelian resumed his fight against the Germanic tribes. Aurelian’s march against Quintillus left the Pannonian frontier open where the Vandals were now massing and preparing to attack. Aurelian returned to Aquileia to start organizing supplies and then marched out of Italy, crossing the Julian Alps into Pannonia. He set up base in Siscia, the mint city of the region, and assumed his first consulship here on the first of 271. A while after the Vandals crossed the river in force and started looting, they began having a hard time living off the land they were invading. Aurelian withdrew food and supplies into fortified cities knowing that the Vandals were ill-equipped for siege warfare. Aurelian then sought them out when they were finally weakened and eventually landed a large victory over them. The Vandals sued for peace and in their treaty promised to stay peaceful. In return, the Romans gave them food and safe passage.

However, Aurelian still had to deal with the Jugunthi. Upstream along the Danube, the Jugunthi took advantage of Aurelian’s preoccupation with the Vandals to spread destruction. The Jugunthi cut from Raetia to Lake Constance before turning south to the Alps, right on Italian soil. Once finished with the Vandals, Aurelian immediately sent his troops down to Italy along the southern edge of the Dolomites through the Via Postumia. As Aurelian neared Milan, he found that the Jugunthi had moved southeast and sacked Placentia. When the Jugunthi were asked to give up, they refused and taunted the Romans before heading further southeast. The Romans, tired from chasing and fighting, were ambushed near Placentia while following the Jugunthi, allowing the Jugunthi to push down the Via Aemilia further toward Rome. Because Rome had long since overgrown its ancient walls, its unprotected citizens were terrified of the Jugunthi menace. This fear caused the previously mentioned Rome riots of 271. Hastily, Aurelian regrouped his army and followed the Jugunthi down the side of the Apennines toward the Adriatic. The Epitome de Caesaribus, attributed to Aurelius Victor, recounts that along the banks of Metaurus, Aurelian caught and trapped the Jugunthi against a river, leading to a decisive victory. The Jugunthi attempted to sue for peace believing they could still negotiate from a position of strength. However, Aurelian was unimpressed and was not going to let such a force laden with Roman spoils roam unchecked in the empire. The Jugunthi were forced to head back up the Via Aemilia, to which Aurelian chased down and defeated the remaining forces.

After the Jugunthi invasion, Aurelian sought to provide a permanent defense for the city of Rome. The Rome riots had been sparked by a fear of invasion, something the city had not been worried about for centuries. For much of Roman history, the city of Rome had been protected by the size of its empire and its army. This was no longer the case. Aurelian did not have the resources to spare leaving a force behind in Rome, but he also could not leave Rome unguarded in fear of another riot. His solution for preventing future riots was pragmatic: he financed and oversaw the construction of defensive walls around Rome, which still stand today. While Aurelian used military architects to draft the plans for the walls, he could not use the army to build the walls since they were needed elsewhere, so he employed city guilds. Aurelian personally oversaw the initial construction of these walls, but the entire project would take the rest of Aurelian’s reign and part of Probus’ reign, his successor. 

To build walls around the whole of Rome would have been impractical. Nevertheless, Aurelian’s walls still ended up being almost 12 miles long. They encompassed most of the fourteen Augustan regions of the city and all structures of economic and strategic importance. The north and south boundaries followed old customs that had been marked by boundary stones set during the reign of the Five Good Emperors. However, a protrusion in the south protected a section of the Via Appia, the aqueduct Aqua Antoniniana, and the northern lip of the Almo valley which was important strategically. In the west, a large salient covered the top of the Janiculum to protect the bridges of the Tiber and the city’s flour mills. The northeast covered a large area around the praetorian camp while the southeast covered the aqueduct systems of the Aquae Claudia-Anio Novus and the Marcia-Tepula-Iulia. The riverbanks were fortified on each side of the Tiber as well. On the east bank, a half-mile long wall was built in the south while a wall three times the length was built in the north. 

Aurelian’s walls were critical defenses that ensured Rome’s protection. The walls themselves were made a core of tufa and covered in cement, while tiles and bricks were placed on the outside. The walls were 12 feet thick and 20 feet tall, regular for military fortifications of the time. Towers punctuated the walls every 100 feet. These were 25 feet across and rose 15 feet above the walls. Stairwells provided access to the top and windows allowed the use of ballistae. Aurelian’s walls also held 29 gates. Four gates held the entrance to the four major roads into the city: the Via Flaminia, the Via Appia, the Via Ostiensis, and the Via Portuensis. The lesser roads of the Viae Salaria, Nomentana, Tiburtina, and Latina also had their own gates. The rest of the gates served minor roads or were mere posterns. 

By building walls around Rome, Aurelian meant to delay sudden attacks by Germanic invaders, like the threat the Jugunthi posed, until Roman forces could arrive. They were built in a hurry and with inexperienced builders, but also had to be imposing rather than ornate. They could not withstand an army equipped with siege weaponry, as exemplified by the large amount of entrances. However, Aurelian’s dedication to building these walls, like his administrative reforms, were to provide security to the city of Rome and prevent a repeat of the 271 Rome riots that would have destabilized his reign.

In the summer of 271, Aurelian returned to handle the Goths and the Danubian border. While Aurelian was building his walls, the Goths were renewing their offensive in Moesia and Thrace. Aurelian arrived in early autumn and defeated the Goths decisively, driving them back across the Danube. However, Aurelian did not stop there, but crossed the river and killed their king as well, effectively securing Rome’s northern border.

After this campaign, Aurelian turned to resolving the situation in Dacia. From the reign of Philip onward, the province had been continuously under attack by Germanic tribes. Gallienus did not have resources to spare on a proper defense, and by the reign of Emperor Claudius, Roman legions were unable to do anything in the region. Aurelian did not have the resources to defend the Danube, restore Dacia, and launch an attack on Palmyra. While he could have enlisted raw recruits from the Balkans for his Palmyrene campaign, the recruits would not have been skilled enough. Aurelian also could not take parts of the Danubian army with him, as that would have endangered the Danubian frontier. Aurelian was forced to make a drastic change. Aurelian’s defeat of the Goths in 271 gave him the authority to overhaul the defense of the region. By withdrawing all forces from Dacia and drawing a new border of the empire along the Danube, Aurelian reduced the territory that needed active troops. He also evacuated important citizens and resettled them south of the river in the new province of Dacia Ripensis with its capital at Serdica, and imposed terms on the Goths. He made sure to not give the impression of weakness. The new Danubian frontier required much less manpower to hold which was important since he had to gather as many troops as possible for his attack on Palmyra. With the tactical retreat from Dacia complete and the major threat of Germanic invasions ended, Aurelian began preparing a powerful force against Palmyra in the winter. In spring, he finally marched to Chalcedon. Although Germanic tribes would show up later during his reign, they were far weaker and less frequent in fear of Aurelian’s military dominance, removing one of the empire’s most destabilizing threats. 

The Emergence of the Gallic and Palmyrene Empires in the Third Century

The formation of the Gallic Empire further added to the burdens the Roman Empire faced during the Crisis of the Third Century. When Gallienus was fighting off the Jugunthi at Milan, the defense of the Rhine was left to Marcus Cassianus Latinius Postumus, a tough soldier from a humble family, not unlike Aurelian. In 260 CE, after the capture of Valerian, Postumus mutinied and the army declared him emperor. The provinces of Gaul, Germania, Britain, and Spain all came under Postumus’ control as the Gallic Empire, as well as Raetia for a short time. Postumus was unique because, for a usurper, it was rare to last so long without ever receiving or trying to receive support from Rome, yet he still assumed the titles and powers of an emperor. Postumus realized that he did not need the recognition of the Roman Senate, given his popularity in the region due to his success against the invading Germanic tribes. He decided to forfeit potentially controlling provinces outside the west and in turn gave himself a more stable position, yet this still cut off important provinces from the Roman Empire. 

While Gallienus dealt with other uprisings, Postumus decided to wait patiently and consolidate his power base. In 261, Gallienus retook the Balkans while the other usurpers had died one way or the other. Postumus was now the only usurper left. By controlling Baden-Wurttemberg though, Postumus was protected against both Gallienus and Germanic invasions from the Danube. Although Gallienus was eager to attack, the situation stalemated when both sides needed to deal with pressures from invading tribes. Postumus’ strategy of non-aggression was therefore very frustrating.

In the mid-260s though, Gallienus found the perfect opportunity to attack. He took with him Aureolus, a very good general but who was somewhat suspect in loyalty. Gallienus won a decisive victory while marching deep into Gaul; however, he was not able to press further due to deliberate hesitation by Aureolus. While this bordered on treason, Gallienus chose to ignore it for now. When Gallienus was forced to retreat because of an injury, the stalemate continued. After Gallienus’ defeat of the Heruli, he learned that Aureolus, whom he had left in Milan to guard Italy, revolted; this forced Gallienus to march on him with Aurelian still by his side. Aureolus minted coins at Milan with Postumus’ name to try to gain his support against Gallienus, but Postumus refused. Gallienus then engaged Aureolus at Pontirolo. However, during this time, senior officers Aurelian, Aurelius Haraclianus, and Marcus Aurelius Claudius plotted to kill Gallienus. Gallienus was assassinated and replaced by Claudius early in September. By simply existing, the Gallic Empire caused an uprising and the assassination of an emperor.

As news reached the senate of Gallienus’ death, Claudius attempted to distance himself from the coup while developments occurred in the Gallic Empire. Aurelian would also continue to rise up the military ranks. After becoming emperor, Claudius quickly curbed the senate’s excessive hate of Gallienus and forced them to deify him in an effort to disassociate himself from Gallienus’ death. Claudius would also kill or at least fire Heraclianus. However, Aurelian seems to have earned Claudius’ trust and was popular with the army. Therefore, Aurelian became commander of the Dalmatian cavalry and later commander of the entire cavalry, with which he helped to secure a victory over the Goths. Aureolus was soon killed, whether by Claudius or overthrown by his own troops Around this time, Laelianus, one of Postumus’ generals, revolted in Mainz. The troops supporting him were likely upset with Postumus and thought that he should have allied with Aureolus. Postumus quickly killed Laelian after besieging Mainz, but he prevented his troops from pillaging the city. This caused them to revolt and Postumus was killed. Claudius considered intervening now, but decided to instead deal with the Gothic invasion in the Balkans, and left his brother Quintillus in Italy instead.

Furthermore, the Palmyrene Empire also formed during this time, threatening the sovereignty of the Roman Empire in the east. The Palmyrene threat was in part caused by the assassination of Odenathus between 267-268. His wife, Queen Septimia Zenobia, seized power with her son Vaballathus. Zenobia was shrewd, capable, and determined. She realized that with Odenathus’ death, everything their family worked for was jeopardized. The transfer of power from someone like Odenathus, who had built up connections by himself, was more dangerous than doing so with an established dynasty. Therefore, she took the initiative to ensure a smooth transition of power by emulating a standard royal succession. Zenobia gave Vaballathus the titles and flairs that his father had, including Roman titles. This ensured that they would preserve Odenathus’ allies and power in Palmyra. Yet even though Vaballathus held these titles, Zenobia was truly in charge after her husband’s death, as the Historia Augusta notes. She further enlisted Zabdas, one of her closest advisors and generals, whose military skill and loyalty she could rely on.

While Claudius dealt with other matters, Zenobia gradually encroached on the Roman emperor’s authority. An unspoken agreement for Vaballathus to use Roman titles existed as long as Zenobia did not fully exploit the titles’ powers to their fullest. However, she was aware of the strength of her position and the weakness of Roman control in the east. In 269, while Claudius and Aurelian were busy in Italy and the Balkans, Zenobia consolidated her forces in the east. She began reclaiming regions that her husband had controlled before his death, including Asia Minor and Egypt, expecting Rome to comply. 

In the spring of 270—while Claudius and Aurelian were still preoccupied—Zenobia sent her general and army into Roman Arabia. The dux of Arabia, Trassus, organized the legendary Roman force III Cyrenaica in response to fight the Palmyrenes at Bostra, the capital. Zabdas destroyed these forces and killed Trassus, sacking Bostra. Zabdas then marched to the Jordan Valley with little resistance. After taking Arabia and Judaea, the Palmyrenes’ next target was Egypt. Tenagino Probus, the most experienced Roman commander in Egypt, was away at a battle with the Goths, allowing Zabdas to easily defeat the Roman forces in Egypt. When Probus returned, he attempted a counterattack but ultimately fell, giving Palmyra full control of Egypt. With this coup, Zenobia effectively controlled the eastern breadbasket of Rome.

Aurelian’s Reincorporation of the Gallic and Palmyrene Empires

Aurelian inherited a divided empire and yet, by the end of his reign, he was able to reconquer the Palmyrene and Gallic Empires. In the east, the Palmyrene queen Zenobia was still tightening her control over Syria to promote the Palmyrene Empire. The mint at Antioch stopped producing coins with Claudius’ name in 270 CE and began minting coins with Vaballathus on one side and Aurelian on the other. By the spring of 271, Zabdas arrived in northern Syria, signaling that Palmyrene control now extended across most of Asia Minor. However, the northwest regions of Asia Minor still resisted the Palmyrenes. Zenobia was unable to take Chalcedon, which controlled of the Bosphorus; moreover, Bithynia and the mint at Cyzicus remained loyal to Aurelian. This would later be the crucial stepping stone to Aurelian’s future offensive against Palmyra. Nevertheless, in 270, Zenobia continued to infringe on Roman authority. In early December of that year, Alexandrian coins featured both Vaballathus and Aurelian. On these coins, Aurelian was titled emperor, while Vaballathus was given everything except full imperial status. By 271, the coins from this mint failed to mention Aurelian at all. This signified Rome’s dwindling power in Asia Minor. Finally, in April of 272, in response to Aurelian’s oncoming offensive, Vaballathus and Zenobia were titled Augustus and Augusta, thereby claiming imperial power in the region.

Aurelian was forced to eventually fight Zenobia in order to liberate the eastern parts of the empire. These provinces were too sensitive to be left in the hands of a potentially hostile power since they provided important tax money, and in the case of Egypt, grain. In fact, Aurelian launched his first attack on Palmyra in Egypt to protect the grain trade. By the third week of June, Aurelian’s forces had taken back Alexandria and the rest of Egypt. The Roman enclave in Bithynia also welcomed Aurelian as he crossed into Asia Minor. Aurelian continued to pass through the region until he reached Tyana, which became the first town to resist when they closed the city gates on him. Aurelian, enraged, swore that not a single dog would be left alive when he was done with the town. After a brief siege, Aurelian forced his way into the city but then decided that, in the long term, a merciful approach would be more beneficial to his reputation. This angered his troops though, which was dangerous since they could have mutinied. The author of the Historia Augusta describes Aurelian’s subsequent actions: 

when the soldiers clamoured for the destruction of the city in accordance with the words in which [Aurelian] had declared that he would not leave a dog alive in Tyana, he answered them, saying: “I did, indeed, declare that I would not leave a dog alive in this city; well, then, kill all the dogs.”

Satisfied by the jest, the soldiers followed Aurelian’s orders and a mutiny was averted. Aurelian was also able to improve his reputation by sparing the town.

Still in the summer of 272, Aurelian took on the bigger challenge of Syria. Zenobia knew that Aurelian’s first step into Syria would have to be Antioch along the Orontes, so she planned to defend it as much as possible. The Palmyrenes decided to place their army north of the city to intercept Aurelian from Alexandria. The terrain there would also be advantageous to the famous Palmyrene heavy-mail cavalry. When Aurelian learned of this, he decided to attack from the east to confuse the enemy and remove the terrain that the Palmyrenes favored. When the Palmyrenes saw this, they positioned themselves accordingly. With characteristic military brilliance, Aurelian baited the Palmyrene cavalry into charging and chasing the Roman army down a road to the town of Immae during a hot May or June day. When the Palmyrenes tired, the Romans turned around and slaughtered them. As he entered Antioch, he pardoned the citizens.

With Palmyra’s greatest weapons crippled, the war was almost over. Marching onward, Aurelian encountered the remaining Palmyrene forces at the city of Emesa. Aurelian attempted the same tactic he pulled off at Immae, however, this time, the Palmyrene troops got too close to the Romans resulting in casualties. The Palmyrenes grew overzealous though, allowing the Roman forces to regroup and surround the Palmyrenes, leading to another decisive victory. On hearing this, Zenobia abandoned Emesa and headed for the safety of Palmyra. Aurelian chased Zenobia through the hot desert, but the queen was able to reach Palmyra in time. Although Aurelian offered peace to Zenobia, she refused because she felt she could outlast a siege. However, she eventually realized that her only hope was aid from Persia. Even though Odenathus built his reputation on the downfall of the Persians, there was a possibility that the enemy of an enemy could be a friend. On one particular night, Zenobia snuck off to ask for help in person, but she was caught by Aurelian. The Palmyrenes immediately surrendered after this, to which Aurelian received them with what was now his signature mercy.

Although Aurelian spared the innocent during his campaign against Palmyra, he severely punished those in charge. Zenobia and the other chief leaders were taken in, while a Roman garrison was placed in Palmyra headed by a general named Marcellinus. The town’s defenses and military equipment were also confiscated, along with much of the town’s wealth in order to pay for the war. At the same time, the Persians did not want war with the Romans and they sent an embassy assuring Aurelian of their goodwill. Aurelian returned to Emesa with Palmyrene captives to put on trial, and many, including Zabdas, were killed. However, Zenobia was spared because Aurelian wanted to parade her on his return to Rome—not out of cruelty, but to quash any lingering sympathies for the Palmyrene cause. 

During his return to Rome, Aurelian learned from Marcellinus that Palmyra had rebelled. The Palmyrenes, resentful at how their city had been treated, took advantage of Aurelian’s absence and rose up. Marching speedily against Palmyra, Aurelian took the city by surprise and easily took out the rebels. Those directly involved were punished, but excessively cruel vengeance was not taken. Still, Aurelian was harsh. Almost all of the city’s wealth was now taken and buildings and city fortifications were vandalized to make sure that Palmyra would never become a threat again. Palmyra never did recover: the desert trade moved north to Batnae while Palmyra became a small and unimportant city. Aurelian finally reached Rome at the end of the year, just in time to assume consulship for 274. Aurelian still needed to deal with the Gallic Empire though, which had been standing since Postumus’ revolt of 260. 

While the Gallic Empire had maintained its political autonomy, it was also experiencing its own political intrigue. When Postumus was lynched at Mainz in 269, it was thought that the Gallic Empire would vanish along with him. However, the Rhine army was afraid that their lengthy disloyalty toward Rome would cause the Roman emperor to punish them. Therefore, they elevated a new emperor, Marius, but he lacked the traits that made Postumus a good leader. Marius was killed a few weeks into his reign and Marcus Piavonius Victorinus took his place. When Postumus died, the Aedui people in Central Gaul switched allegiance to the Roman Empire. In early 270, Victorinus marched on the Aedui in their primary city of Augustodunum. The Aedui asked for help from Claudius, but he was preoccupied with the Goths and only placed a garrison to guard Italy against Gallic attacks. The garrison was told to not intervene in the siege of Augustodunum. When the city finally fell, Victorinus allowed his troops to sack the city to great devastation. In the spring of 271 though, Victorinus was murdered in Cologne for his affairs with his officers’ wives. He was succeeded by Gaius Pius Esuvius Tetricus, governor of Aquitania. Although Aurelian’s military reputation had been well established, Tetricus knew that Aurelian could not focus on him for now because the Goths and the Palmyrene Empire posed bigger threats to the Roman Empire. 

When Aurelian returned from the east, he finally set his sights on taking the Gallic Empire. At first, Tetricus’ reign seemed secure, with a Rhine army ready to serve him. His campaigns against the Franks were successful, but he soon experienced financial difficulties. In 274, his relationship with the army began to sour as the threat of Aurelian came closer. An uprising in Belgica shook Tetricus and weakened his authority even though he put it down. In the spring of 274, Aurelian was still in Rome conducting administrative duties, including his famous reforms; however, by early summer, Aurelian prepared to battle Tetricus. He crossed the Alps by the Little St. Bernard Pass to Narbonensis and then marched up Rhone and Saone, taking Lyon. Tetricus drew up a force to stop Aurelian at Chalons-sur-Marne, but Aurelian’s superior military prowess won the battle, taking Tetricus prisoner and ending the Gallic threat.

With Tetricus captured and sent to Rome, Aurelian remained in Gaul to reintegrate the provinces and secure the Rhine frontier. To integrate the west smoothly, Aurelian chose not to condemn the memory of Tetricus and allowed those already in power in the west to continue holding power. He also replenished garrisons and strengthened physical defenses along vulnerable towns. Meanwhile, the role of the Rhine army as kingmaker was at an end for now and their allegiance quietly returned to Rome. However, Aurelian did move the Gallic mint from Trier to Lyon since the proximity of the mint to the border was dangerous. In autumn, with the existential threats of the Palmyrene and Gallic Empires gone, Aurelian finally left the frontier to his subordinates and returned to Rome to celebrate.

Conclusion

While Aurelian’s military and administrative accomplishments restored the empire, he shared the fate of his predecessors: an early death. In 275 CE, Aurelian campaigned in Gaul, Raetia, and the Balkans once again. After a campaign along the Danube in the summer of 275, Aurelian headed for the east when he was killed in autumn. A slave working for Aurelian’s secretarial staff tricked Aurelian’s men into killing him, forging a document that stated multiple officers close to Aurelian would be punished. Aurelian’s death shocked a Roman world that had grown numb to regicide. He had earned the respect of his troops and officers, who mourned him. Even the conspirators, once they realized they had been fooled, were remorseful. His assassins could not even choose a replacement.

Although Aurelian’s reign was short-lived, his accomplishments allowed his successors to end the Crisis of the Third Century. Aurelian was the epitome of the new breed of Roman emperors during the Third Century: a military commander first and foremost. Through his military efforts, he averted the permanent disintegration of the empire and allowed it to survive for another 200 years. Unlike many of his predecessors though, Aurelian balanced military victories with innovative solutions to the economic ills of the empire. He was highly conservative and loyal to the traditions and integrity of the Roman Empire, but did not hesitate to relinquish Dacia to save resources or shut down the mint at Rome when it started defrauding the monetary system. He reformed the debased coinage and mint system, and in order to provide food security he increased the urban food dole. Emperors a decade after Aurelian’s reign conclusively ended the Crisis of the Third Century, but in just five years and two months, Aurelian inspired hope in the empire once again.