Who was the Greatest Roman Emperor?
Before I begin, this article is opinion. Whether you agree or disagree, I would like to hear your thoughts. It was a fun exercise in history that I chose to pursue in the hope of creating a conversation on this subject.
Criteria
What makes a Roman emperor either good or bad? Do we reward the emperors who had military prowess and kept the enemies of Rome subdued over emperors who chose a policy of peace? How do we rate emperors from different eras? Should we judge emperors solely on their accomplishments during their lifetime or should we also judge them on their successors?
While many different historians may answer these questions differently, we will try to follow the philosophical framework derived from “WAR”, wins above replacement. In baseball, WAR measures how a player compares to the average replacement-level player in a similar position. In a similar vein, we will try to measure the success or failure of an emperor and his policies by comparing their results to a theoretical expectation we would have if the empire were run by an “average” emperor.
If we find that the emperor exceeded expectations per his situation, then we will reward him for that success. This hopefully controls for differences in policy and political climate for each emperor. While in baseball there is a quantitative aspect to WAR, it would be impossible to measure Roman emperors using an equation. As such, the conclusions will be qualitative and could be debated.
While we will rank the Top 15 emperors, we will also classify them in tiers. This would allow us to give further analysis on emperors that were rated closely. We will also not judge emperors after the collapse of the Western Roman Empire. With all apologies to Justinian and other great emperors after 476 AD, we want to limit the scope of emperors that were ranked and when Rome fell seems to be the perfect spot. So, without further ado…
B Tier
The emperors in this tier were generally good emperors but were held back from a higher ranking due to a fatal flaw in their resume. This could have been due to a lack of longevity, unable to accomplish their main goal, the state of the empire after their rule, or relations with other powerful factions in the republic.
15 — Nerva (96–98 AD)
The founder of the greatest dynasty in Rome and one of the “Five Good Emperors,” one may suspect he achieved greatness during his reign.
After looking into his reign, one may question how he is one of the “Five Good Emperors.” With a reign of over a year, Nerva’s one and only issue was to deal with Rome after the assassination of Domitian. While he did prevent a civil war, he had to deal with an unhappy army that was more than happy to exercise its power.
Due to this, Nerva could be seen as more of a placeholder for his successor. However, his pick (Trajan) proved to be incredibly successful. So while his accolades may be lacking, the company that he keeps deserves some recognition.
14 — Majorian (457–461 AD)
Perhaps one of the most underrated emperors, he was “the only man to hold that office in the 5th century who had some claim to greatness” (Britannica).
If Majorian had a few more years or if his fleet was not destroyed by traitors, he may have accomplished his goal. His goal was to rebuild Rome to its former glory. If successful, Rome may have survived for another couple of centuries; similar to Aurelian and how he fixed Rome in the crisis of the 3rd Century.
While Majorian had successes and almost brought the empire back from a terminal decline, he was not successful due to a series of betrayals that ultimately led to his assassination. What could have been?
13 — Septimius Severus (193–211 AD)
After the fall of Commodus, Rome had a power struggle between different parties. The winner was Septimius Severus.
His reign could be described as successful and cruel. Like Domitian, the Senate did not like Septimius Severus. However, he used force to end his enemies and put allies in positions of power. Through his reforms, we can see the dichotomy of his reign.
While reducing the power of the Senate, he increased the power of the military. In fact, one may say his political strategy was to increase the power of the army and to keep the soldiers happy. This strategy worked for Rome as long as the man in charge was competent and Septimius Severus was a competent emperor.
However, if an emperor who was cruel, corrupt, and incompetent were to take over, then Rome would be in trouble. Unfortunately, Septimius Severus’s sons would fall into this category. Ironically, for a man who blamed Marcus Aurelius for Commodus, he gave Rome Caracalla.
This also created an atmosphere where Roman legions would select future emperors and not the Senate. If the emperor made the soldiers unhappy, they would choose a new emperor. Different legions would also not recognize emperors selected by other legions.
While Septimius Severus may not have directly caused the crisis of the 3rd Century, he sowed the seeds. Regardless, the Principate died under the Severan dynasty.
12 — Titus (79–81 AD)
If Titus had a long reign, he may have been one of Rome’s great emperors. Unfortunately, his reign only lasted two years.
While he had a short reign, he did face serious challenges. After the eruption of Vesuvius and a fire broke out in Rome, he led and organized the relief effort by charitably giving his own money for support.
He was also the emperor when the Colosseum was completed and opened the arena to many games and much fanfare. Similar to Majorian, we could only imagine what could have been if he ruled for a significant period of time.
11 — Domitian (81–96 AD)
In many ways, the reigns of Domitian and Titus were polar opposites, despite being brothers. Titus was universally loved and had a short reign; Domitian had a long reign and was hated by the Senate.
However, both brothers were successful in their reigns. In fact, if we were to base this list only on policy successes or failures, Domitian would have been ranked much higher. The empire’s bureaucracy ran well when he was emperor and he may have been the only emperor who successfully tackled inflation. His successes were due to his management style.
His failures were also due to his management style. If Domitian were to rule during the Dominate era, he would have fit in perfectly. Unfortunately for him (and perhaps even Rome), he ruled during the height of the Principate. In this era, while the emperor had the power, he still heeded and respected the Senate.
Domitian did neither of these things. He wanted to rule the empire his way, with his policies, and with him in charge. This made a number of enemies within the Senate. While being loathed by the Senate would not prevent an emperor from being rated higher, being assassinated by them does. If Domitian altered his management style to better incorporate the Senate, he may have been one of Rome’s greatest emperors.
B+ Tier
These emperors in this tier may not have had the same level of success as the other emperors ranked higher on this list. However, their major success was to bring peace to an empire in turmoil.
10 — Claudius (41–54 AD)
During the reign of Augustus, no one thought Claudius would be an emperor. However, through a series of events, Claudius found himself rising to the role of emperor after his nephew Caligula was assassinated.
While he was usually found on the sideline, when he finally came into power, Claudius did well. He expanded the empire and improved Rome through public works. However, his greatest success could be defined as healing the empire.
After the disastrous reign of Caligula, Rome was bloodied and bruised. After the insanity and transgressions of his predecessor, Claudius not only put Rome back on solid footing but preserved the Julio-Claudian Dynasty. While other emperors were better statesmen, Claudius with a deft hand not only put Rome on track but elevated it. Unfortunately for all of his hard work, he left his empire and dynasty to Nero.
9 — Vespasian (69–79 AD)
After the fall of Nero and the Julio-Claudian Dynasty, there was a new and first opportunity for an outsider to be emperor.
At the end of the day, Vespasian would take the reins of power and establish the Flavian dynasty. Similar to Claudius, he focused on public projects for Rome, including the Colosseum, and brought peace to troublesome provinces. While some of the policies were controversial, he was willing to amend them as needed. He ruled Rome with a firm hand but was not cruel.
However, his biggest achievement was bringing peace back to the Empire. After the largest civil war since the end of the Republic, Vespasian was able to unite the empire under his rule. After the Year of Four Emperors, he worked to restore Rome after the reign of Nero. His decade in power improved and restored the Roman Empire. His successors would continue the legacy and it was the second greatest dynasty in Roman history.
A Tier
These men could be considered great emperors. They were all successful and Rome prospered due to their reigns.
8 — Marcus Aurelius (161–180 AD)
Perhaps the smartest man who became emperor and the last of the Five Good Emperors, Marcus Aurelius certainly left behind a legacy that is celebrated today.
Selected from a young age to eventually rule the Empire, he was able to meet such lofty expectations. While selected by Hadrian to be a future Emperor, he had to wait through the reign of Antoninus Pius to take over control of the empire. While at first he co-ruled Rome with his brother, it was clear that Marcus Aurelius was the first among equals.
If Marcus Aurelius was fortunate in his rise to power, he was unfortunate with the events surrounding his reign. With wars against Germanic tribes and Parthians, Rome was tested on multiple fronts. While tested, Marcus Aurelius answered the call.
The Romans overcame the Parthians; the Germans were pushed back. While the Macromannic Wars were not a decisive Roman victory, to blame this all on Marcus Aurelius would be unfair.
First and foremost, the empire suffered from the Antonine Plague. While we are unsure of the specific disease that afflicted Rome, it nevertheless caused a significant impact on the empire. Even when this serious challenge, Marcus Aurelius may have had a decisive victory if he had not died first.
If Marcus Aurelius was an average emperor, Rome may have been in a crisis a century sooner. Between the challenges from foreign enemies and diseases, to be able to keep Rome running and running well is a testament to him. Why not rank him higher? Because he was the last of the Five Good Emperors.
His son and successor, Commodus, took control of Rome. Commodus may be the worst man to ever lead the empire. If he was not the worst, he is certainly in the discussion. If Commodus were to never don the purple, perhaps the Pax Romana would have continued; especially if the next man was a man of merit. But no, we are stuck with Commodus.
With this fateful decision, the Pax Romana died and the Principate was left in tatters. Yes, the Severan Dynasty may have killed the Principate; but they only finished the work started by Commodus. If Commodus was so terrible for the empire, why not rank Marcus Aurelius lower?
Well, Commodus was still Marcus Aurelius’ son. So while Commodus was terrible for the empire, it is somewhat understandable why Marcus Aurelius made this decision. Plus, a father’s reign should not be punished for the sins of the son.
7 — Diocletian (284–305 AD)
While one may argue whether Diocletian ended the Crisis of the Third Century, there is no question that the reforms of Diocletian allowed Rome to survive another two centuries.
While Diocletian may be considered the inventor of the Dominate system that followed the Principate, the reforms that transformed the empire started before his rule. Nevertheless, Diocletian set out to reform Rome to bring back order to the empire that descended into anarchy.
This includes an empire-wide bureaucracy, military and economic reforms, and the Tetrarchy. The essence of the empire was altered throughout his reign. So in order to judge the success of Diocletian, we must judge his reforms.
His reforms in the short term rebuilt Rome and allowed it to survive. In the long term, his reforms most likely hurt the western half of the empire. Creating policies that allowed rich landowners to live outside the system, reduced the resources recuperated by the state. Without these resources, the West had trouble surviving the barbarians in the 5th century.
However, it would be unfair to Diocletian to blame him for his policies in the 5th century when there were emperors in power who could have changed the system before they became an issue. If Diocletian’s goal was for Rome to be institutionally strong for the next century, then Diocletian was successful in this regard. It would be folly to attribute failures to his system when changes could have been implemented.
However, this does not mean all of his policies were successful. Perhaps the policy he most passionately pursued was a Rome divided among four men. Due to the empire’s great size, Diocletian believed that multiple men needed to rule. Having two senior emperors with each a junior emperor, it would allow a peaceful transition of power and more effective leadership on top… in theory.
In truth, the Tetrarchy died before Diocletian did. After Diocletian voluntarily resigned, a power struggle emerged within the Tetrarchy which eventually led to the rule of Constantine. While this reform proved ineffectual, future emperors did split the empire with similar goals to Diocletian.
6 — Constantine (306–337 AD)
The man who ended the Tetrarchy, Constantine could join Diocletian as the two most influential Roman emperors after the Five Good Emperors. While Diocletian could be credited for much of the Dominate, by the end of Constantine’s reign, the evolution of the Dominate was complete.
While Diocletian was a Pagan emperor who at times persecuted Christians, Constantine was the first emperor who welcomed and accepted Christianity in the empire. Diocletian created the Tetrarchy in order for Rome to be better administered, Constantine smashed the Tetrarchy so he could administer all of Rome.
While he is often compared to his predecessor, it is important to note his own personal achievements. Arguably his greatest achievement was the construction of the Second Rome, Constantinople. While Rome and the West would only be a center of power for another century and a half, the Eastern half would go on for another millennium.
One of the great cities of the Middle Ages, it was home to Rome when there was no Rome. Without the city’s namesake, who knows how Rome would fare in the future?
A+ Tier Discussion
The reason why I did not rank the prior emperors higher is because the next leaders all elevated Rome to heights either unreached or unthinkable. These emperors were able to build upon the successes of their predecessors, but their accomplishments were not as great or as long-lasting.
Marcus Aurelius handed the empire to a sociopath. Diocletian’s Tetrarchy died before he did. While neither criticism could be applied to Constantine, his successors were also lacking. Furthermore, in his case, his reign was the last time Rome had the sun shine upon the empire. After Constantine’s reign, the last pages of the empire were being written. Except for the paragraph about Majorian, the story was about decline. The next emperors either raised Rome to heights the empire had never seen before or after or led the greatest comeback in the history of the empire.
5 — Hadrian (117–138 AD)
Before Hadrian, Rome was continuously growing. Because of Hadrian and his policies, Rome no longer was a growing empire.
In fact, the empire would never be as large as it was during the reign of Hadrian’s predecessor, Trajan. Usually when an empire stops growing, this is due to failures within the empire. For Rome, this was not the case. Instead, Hadrian pursued a pragmatic policy of defending the empire.
This meant having defensible borders and making borders defensible. The prime example of this policy is Hadrian’s Wall in the United Kingdom.
However, this drastic change in policy was not the only policy pursued. He reformed the legal system which would later be the base of later Roman reforms to the legal systems. He traveled all across the empire, particularly Greece, in order to improve the territories in the empire.
He built and rebuilt great public works wherever he went. Such improvement usually had the direct involvement of the emperor. While micromanaging could lead to uneven results, in the case of Hadrian, Rome prospered due to his detailed involvement.
If we were to judge emperors solely on their success, it is likely that Hadrian would rank higher on this list. Not only was he one of the Five Good Emperors, but the 2nd century was perhaps the greatest of all Roman centuries; with Hadrian being one of the reasons for this success.
Not only was he successful, but his hand-picked successors Antonius Pius and Marcus Aurelius also added to his legacy. However, there are two significant items that hold Hadrian back. The first and foremost is his strategy of defense instead of expansion. While overall this strategy was successful, there was one area where this strategy was implemented that may have hurt the republic.
Right before Trajan’s death, Rome conquered Mesopotamia from the Parthians. As soon as he died, Hadrian decided to fall back from this position. It is entirely possible this was the correct call. However, if Rome was able to keep Mesopotamia, this may have taken out the Parthians and any future Persian challengers at the knees.
With this land, it would have been easier to trade with India thus bypassing Parthia on the Silk Road. With reduced revenues, Parthia would have trouble keeping up with the Romans. While I do not believe Rome would have been able to conquer and keep Parthia and the Persians, it is likely that Rome’s greatest single foe during the Empire would have been significantly weaker.
With such strategic interests, perhaps this province should have been treated more like Dacia. While Dacia was harder to defend, its mines made Rome wealthy. So if Hadrian kept these lands, it is entirely possible that Mesopotamia could have been the “eastern Dacia.”
The other issue was his relations with the Senate. While not as troubled as Domitian’s relationship with the political elite, there was no love lost between the two sides when Hadrian died. Due to Hadrian’s focus abroad, reversal of expansionist policies, and his behavior towards the end of his rule, the Senate disapproved of Hadrian throughout his reign.
If it was not for his successor Antonius Pius threatening to resign, Hadrian would have not been deified. While the relationship was not as acrimonious as Domitian’s reign, when comparing other great emperors, these slight blemishes seem to loom large especially compared to other great emperors.
4 — Aurelian (270–275 AD)
This may be the hardest man to judge on this list. Every other emperor in the Top 11 reigned for at least a decade, except for Vespasian and Aurelian. The former reigned for almost ten years and the latter’s reign was for about five years.
While Aurelian did have large projects, such as the Aurelian walls in Rome, Aurelian’s reign comes down to his greatest success. He was the Restitutor Orbis or the Restorer of the World. While Diocletian must be given much credit for creating stability after the Crisis of the Third Century, Aurelian deserves the most credit for ending the Crisis of the Third Century. While Rome would not fully move past the Crisis of the Third Century until Diocletian took full control of the Empire, let us examine Rome before and after Aurelian.
Before Aurelian, Rome was beset with a series of troubles. This includes but is not limited to barbaric invasions, political instability at the top, and Rome itself being divided. When Aurelian took over, Gaul and Britannia were ruled by a “Gallic Empire” while the East was ruled by the Palmyrene Empire.
It is not hard to imagine an alternate reality where Rome fell in this period. In fact, if one was a betting man, one would have thought Rome would have disintegrated during this time. How could an empire survive such domestic turmoil and foreign pressures?
Aurelian success is perhaps unfathomable. By the end of his reign, there was Rome and only Rome. The Gallic and Palmyrene Empires were brought back into the fold. The barbaric invasions stopped and the invaders were defeated.
Monetary policies were implemented and provinces that were no longer profitable were deserted. Rome’s frontiers were secured and Rome was united. If it were not for a forged document that led to his assassination, perhaps Aurelian could had even greater success.
While an assassination would usually lead to significant criticism, the perpetrators were lied to by one man and almost immediately regretted their actions; especially when they found out the document that motivated their actions was a forgery.
Unlike Domitian, it was not in response to his reign or his relationship with the powers at be. While his short reign makes it harder to rank him higher, if we were to base an Emperor on only one sole achievement, Aurelian would have ranked as the greatest.
3 — Antoninus Pius (138–161 AD)
In many ways, Antoninus Pius and his predecessor have many similarities and differences. Both pursued a policy of protectionism and the Rome was administered well during each’s reign.
However, there were significant differences. While Hadrian spent most of his reign traveling the empire to ensure it was managed well, Antoninus Pius spent his reign in Italy. Hadrian liked to manage projects closely, and Antoninus Pius managed projects through intermediaries. If Hadrian’s reign could be described as eventful due to the activity of the emperor, Antoninus Pius’s reign was conservative in nature.
Hadrian focus was on the outer territories of Rome; Antoninus Pius’s reign may have been the last time the Italian elite had so much power in the empire. This is not to say one style was better than the other because both were successful and administered by able men, simply these two men had two different governing styles.
While Hadrian could be credited with more policy successes, Antoninus Pius could point to his ability to rule. While himself a Senator, he also remembered that he was an emperor for all Romans. While he remained vigilant about Rome’s treasury, he was generous with his own money.
As such, it is easy to see how the soldiers loved him, the average man loved him, and his former colleagues also loved him. While Rome did have wars during his reign, it was the most peaceful time in the empire. There was both domestic and foreign tranquility.
While some may criticize him for issues that arose during the reign of Marcus Aurelius, we find these criticisms to be unfair. Yes, the Parthians did attack after Antoninus Pius died. But Marcus Aurelius, through his brother, was able to push the Parthians back. This shows the Parthians’ respect for Antoninus Pius and that Rome’s army did not waste away under his rule.
The barbaric invasions that happened five years after Antonius Pius’s death would have likely been pushed back except Rome experienced significant troubles due to pandemics. But even in this situation, Marcus Aurelius was hardly a new emperor when the barbaric north attacked Rome; hardly fair to blame Antoninus Pius for this issue as well.
Instead, let us focus on his reign. If no news is good news, then Antoninus Pius’s reign was the best news for Rome. When historians talk about his reign, it is a reign that beckons comparisons to a golden age.
It is no accident when historians think of the height of the Pax Romana, it was when Antoninus Pius ruled. To be able to rule a land at its height so competently and without complaint should bear witness to the greatness that is Antoninus Pius.
S Tier
While the emperors in the A+ and A tiers were great emperors and stood proudly in a Roman Pantheon of Great Men, there were two men who seemed to be at the head of the table.
When emperors were coronated, they were wished “felicior Augusto, melior Traiano” or “that he be luckier than Augustus and better than Trajan.” In this ranking, I supposed it is better to be lucky than good.
2 — Trajan (98–117 AD)
If you were to google a map of the Roman Empire, in all likelihood you would see the empire Trajan created. Trajan took the empire to heights not seen before his reign.
After his reign, Rome would never reach those heights again. While he technically did not create the Nerva-Antonine Dynasty, he was its first truly great emperor and one of the Five Good Emperors.
If we were to define Trajan’s reign by one word, it would be successful. His military expeditions were successful. Both Dacia and Mesopotamia would be added to the empire. His public projects were successful. Some of his works can be seen today. His relationships with other political powers were successful.
He was loved by everyone, including future historians from the medieval and Renaissance eras. There was nothing Trajan could accomplish during his reign. If Rome’s greatest century was the 2nd Century, this was due to the four men.
These men were the Five Good Emperors, except Nerva. Unlike the other men, Trajan constructed the foundation for this success. It would be easy to rank Trajan as the greatest emperor, however, we believe there is one man whose reign was even better.
1 — Augustus (27 BC-14 AD)
Perhaps there comes a bias for being the first. Looking at American politics, all presidents were and are compared to the greatest founding father, George Washington.
In a similar vein, Augustus is the emperor to whom all others are compared. Before Augustus, there was no empire and no emperor. Instead, there was a republic and civil wars. The republic was an impressive institution when it was running well.
By the time Augustus was born, the republic was not running well. Instead, it was on its last days. There were multiple civil wars and political upheavals that shook Rome. When Augustus won the last of these civil wars, he would bring peace to Rome by making the empire.
With a culture that despised monarchies, this should have been impossible. Yet, Augustus was able to succeed due to the Principate. While it would be correct to say that even during the beginning of the Principate, the power was in the hands of the emperor, it was the genius of Augustus that allowed the Senate to maintain functions during his reign.
This allowed Augustus to rule and allowed the Senate to have a say in public policy. While Augustus would have the first and last word, by keeping the Senate, the people did not despise the first emperor. It also allowed Rome to keep the meritocratic nature that served it so well during the republic.
It was a successful transition and stability from a civilization that experienced a century of political turmoil that required a deft hand and political brilliance. With such skills, it is easy to see how a city of bricks became a city of marble.
