On 18 September, 96 AD the Year of the Four Emperors threatened to repeat itself when the Emperor Domitian was murdered in his palace. A son of the much-beloved Vespasian, Domitian had ruled as Roman Emperor for 15 years after the deaths of his father and older brother. Domitian was popular with the Roman army but hated by most Roman senators for refusing to pay lip service to the Senate’s admittedly limited role in imperial politics. This didn’t seem to bother the emperor; Domitian was an autocrat, and apparently he saw no reason why he shouldn’t behave like one.
However, as the years went by Domitian, much like Nero, became increasingly erratic, suspicious, paranoid and violent. He began to believe that everyone around him was plotting to kill him and treated them accordingly. Unwarranted arrests, baseless convictions for treason and summary executions now became a common fate of any senator or courtier Domitian suddenly decided might be a political opponent.
But if Domitian thought that this violent tyranny would make him safer, he was wrong. His behaviour left even those closest to him living in a state of constant terror, and eventually the emperor’s paranoia became a self-fulfilling prophecy. No one felt safe anymore.
In 96 AD a group of Domitian’s closest companions and confidants, united in fear of their emperor, hatched a desperate plot to kill him before he decided to kill them. On 18 September the conspirators set their plan into motion. At around noon a group of imperial court officials, all conspirators, entered Domitian’s private apartments in the palace. There they found the emperor sitting at his desk, sorting through paperwork. Drawing concealed daggers, the conspirators rushed him. A brief but vicious struggle ensued; by the time it was over Domitian was dead, and one of his assailants fatally wounded.
Emperor Domitian had died without an heir to his throne. For the second time in less than thirty years, a Roman imperial dynasty had become extinct. Any Roman old enough to remember what had happened in 69 AD had good reason to fear the events of that terrible year would repeat themselves but this time, remarkably, they didn’t. Instead, events allowed for a smooth transition of power from the slain Domitian to what would become Rome’s new imperial family.
This family, later called the Antonine dynasty, would prove itself the greatest of Rome’s imperial dynasties. It would rule the Roman Empire for a century and preside over the peak of the Pax Romana, the Roman world’s greatest era of prosperity, stability and cultural achievement. It would provide Rome with a total of seven emperors, and five of these would be remembered by later historians and intellectuals as the Five Good Emperors of Rome: Nerva, Trajan, Hadrian, Antoninus Pius and Marcus Aurelius.
The Imperial Anomaly
How did the Roman Empire succeed in avoiding a civil war in 96 AD, when it had failed to prevent one in the same situation back in 69 AD?
Largely it was thanks to the Senate, which reacted to Domitian’s assassination with unusual speed and decisiveness. Whether or not some of the senators had been informed of (or involved in) the plot against the emperor, they all knew Domitian was dead within hours of his murder. Before the day was over, the Senate had convened to nominate Domitian’s successor.
The need for haste was clear. The Senate needed to have a new emperor appointed before news of Domitian’s murder could reach the legions on the empire’s frontiers and ambitious army generals could be tempted to seek the throne for themselves. Since Domitian had left no heir the Praetorian Guard could not pressure the Senate to appoint anyone in particular as Domitian’s replacement; it could only urge them to choose someone, and fast. For the first time, the Senate had the opportunity to appoint one of their own as the next emperor without much external pressure from the military or a powerful imperial family. It was a right the Senate had always had in theory but rarely in practice, and the senators were determined to make the most of it. The man they chose was Marcus Cocceius Nerva.
The new emperor was in many regards an unusual choice for the imperial office. On the one hand, Nerva was a distinguished civil servant with decades of government experience who had served as an advisor to Domitian. On the other, he had little military experience. He was already 65 when he took the throne, making it unlikely that he would rule for long. He had no sons (and therefore, no obvious successor). Finally, Nerva was not popular among all elements of Roman society. He was not well known to most of the general public, and the army and the Praetorian Guard, both of which had loved Domitian, were not impressed by the thought of a civilian as their new commander-in-chief.
During his brief reign as emperor, Nerva had two chief priorities: to make sure that his unpopularity with the military did not grow into outright rebellion, and to secure the imperial succession by providing an heir to the throne. Luckily for Nerva, he was able to find a single solution to both of these problems: late in 97 AD he adopted a popular army general, Trajan, as his heir and immediately began sharing power with him by granting a consulship to his newly-adopted son. Shortly after, Nerva died of a stroke on 28 January, 98 AD, and the Roman Senate assembled to declare the absent Trajan their new emperor on the same day.
In retrospect, Nerva’s adoption of Trajan would be the most significant thing he ever did in either his long life or his brief imperial tenure. It is the central reason for which Roman history remembers him well. By adopting Trajan, Nerva went from being a non-dynastic Roman emperor to the founder of a new imperial family.
Trajan the Magnificent
On the day he was declared Roman Emperor Trajan was not in Rome, but with his soldiers on the Rhine frontier. Confident that his position in Rome was secure, Trajan did not hurry back to the capital to consolidate his power as soon as he received news of his adoptive father’s death. Instead, he made a long inspection tour of the Rhine and Danube legions to make sure the empire’s frontiers were secure before finally reaching Rome in the summer of 99 AD, over a year after Nerva died.
The fortuitous combination of Trajan’s talents, personality and circumstances made it possible for him to become one of the most popular emperors in Roman history. Trajan was highly regarded by every demographic of Roman society. Ordinary Roman citizens loved him for his common touch, for being the sort of friendly, genial man who would offer any random passerby a ride in his litter. The Roman army loved him for his willingness to lead them on campaign in person, sharing in their hardships and their glories. The Roman Senate appreciated him for his willingness to share, or at least appear to share, the responsibilities of running the empire with them instead of walking all over them the way Domitian had done. With Trajan at the helm, the Roman Empire could bask in a long and glorious reign of foreign conquests, imperial philanthropy, and prosperity and security at home.
The Dacian Wars
The first of Trajan’s priorities was a war of conquest, and the new emperor knew just where to look for one: Dacia. The Dacians were a powerful and warlike barbarian people who lived north of the Danube River. They ruled a large and prosperous kingdom comprising what is now most of Romania. From around 86 AD onward the Dacians had begun raiding and pillaging Roman provinces south of the Danube on a wide scale, prompting then-emperor Domitian to respond with force of arms.
Domitian may have been an enthusiastic soldier, but he was not a talented one; he and his generals never really secured a decisive victory over the Dacians. Instead, Domitian began paying the Dacian king, Decebalus, large annual tributes of gold in return for stopping his warriors from raiding Roman lands. It was not a popular solution; Romans all across the empire were embarrassed, even offended to think that the Roman Empire, the greatest and strongest nation in the world, was paying protection money to barbarians.
Trajan, though, was a far better soldier than Domitian, and he did not intend to continue paying Domitian’s tributes. Instead, the new emperor wanted to find a more forceful answer to the Dacian question. For the first few years of his reign Trajan prepared for war, strengthening the Danube frontier by building new forts along the river and transferring additional military units from elsewhere in the empire to garrison them.
By 101 AD, Trajan was ready for war. The emperor swept into Dacia with the full might of the Roman army behind him. Within a few months the war was won, but Trajan wanted to appear benevolent in victory so he allowed King Decebalus to keep his throne. In return Decebalus had to pledge his loyalty to Trajan and Dacia became a Roman client kingdom, serving as a buffer zone between Rome’s Danube frontier and any potentially hostile barbarian peoples further to the north.
For a brief time Decebalus abided by Trajan’s peace terms, but he had no intention of remaining loyal to Rome in the long run. Before long he was again allowing his warriors to attack Roman lands, as well as trying to convince other northern tribes to join his cause against Rome. In 105 AD, the emperor decided that enough was enough. Trajan returned to the Danube frontier and led a second invasion into Dacia. By the summer of 106 AD the Roman army was at the gates of the Dacian capital. Knowing the war was lost but determined not to be taken prisoner by his enemies, King Decebalus instead took his own life.
Trajan’s second war against Dacia was finally over, and this time the emperor’s peace terms were much less lenient. The Dacian kingdom became a Roman province, its people became imperial subjects and the fallen king’s enormous personal fortune, perhaps as much as half a million kilograms in gold and silver, was handed over to Trajan.
Despite the grim necessity of fighting a second war in Dacia the final outcome was a triumph well worth celebrating, both for Rome and for Trajan. Dacia was a mountainous region rich in natural deposits of gold and silver, and its mineral wealth would make it a valuable addition to the Roman Empire until late in the third century AD. Aside from that, Trajan was able to use Decebalus’ treasure hoard to reward his soldiers, pay for spectacular gladiatorial games and chariot races to impress the Roman public, and fund the construction of great new public buildings, monuments and roads both in Rome and elsewhere in the empire, some of which can still be seen today.
Trajan and the Parthians
For the next few years Trajan ruled peacefully, devoting his attention to civil administration instead of military conquest, but in 113 AD the emperor began a new war of expansion against Rome’s longtime eastern rival: Parthia. This time Trajan was less successful. In the short term Trajan’s eastern campaigns may have looked like a repeat of the Dacian Wars, with the emperor conquering new lands and smashing his enemies in battle wherever they challenged him, but a broader perspective revealed a very different situation.
Parthia was much larger than Dacia; the Parthian army was large and mobile enough that it could afford to lose battles and territory to the Romans without being backed into a corner. Trajan had captured large amounts of Parthian territory, but these new lands had open frontiers without significant natural boundaries and local populations loyal to the Parthian king.
In both geography and culture, the land and its people were much closer to Parthia than to the Roman East. This made controlling these new eastern territories a difficult prospect for the Romans and, in the long term, an uncertain one.
As the war with Parthia dragged on year after year, Trajan’s health began to fail. Early in 117 AD the emperor, sick and exhausted, gave up the campaign and began traveling back to Rome. He never finished the journey, dying of his illness at the age of 63 in Asia Minor on 8 August, 117 AD. Since he had no sons of his own Trajan apparently adopted Hadrian, his first cousin once removed as his son and successor on his deathbed, though there is some uncertainty surrounding this claim.
The Emperor’s Little Cousin
Hadrian would go on to become one of the more colourful Roman emperors, although the earlier years of his life were not particularly remarkable. Like Trajan he was born in southern Spain, where he spent his childhood. Hadrian’s parents died when he was ten years old, and four years after that he was sent to live with his cousin Trajan, who became the teenager’s legal guardian and looked after him from that point on. Like Trajan, Hadrian began his career with military service. He soon attained the rank of legionary tribune (the equivalent of a low-grade senior officer), possibly through Trajan’s endorsement and held that rank for several years, suggesting at least capable if not outstanding performance.
Hadrian’s life began to change dramatically in 98 AD, when Trajan became emperor. As his cousin’s star continued to rise, so did his own. In 101 AD Hadrian began his career in politics, holding a number of lower-level senatorial offices in succession. He served in the army through both of Trajan’s Dacian campaigns, commanding a legion of his own, and was appointed a provincial governor after the wars ended.
In 117 AD Hadrian was serving as Roman governor of Syria when he was told Trajan had died, naming the absent Hadrian as his successor. The facts regarding Trajan’s ‘adoption’ of Hadrian are very murky; it’s possible that Trajan died without naming any heir and that the adoption documents were only drawn up after his death by Trajan’s wife, who wanted Hadrian to be her husband’s successor. Regardless of whether the adoption was genuine or not its endorsement, along with Hadrian’s experience qualifications were enough to convince both the Senate and the military to accept him as the new emperor.
As emperor, Hadrian advocated a change in policy from his predecessor. Trajan had used the Roman army to pursue a policy of aggressive imperial expansion but Hadrian (and later, his successors) decided it was in Rome’s better interests to reverse this. From now on, the Roman Empire would strengthen and consolidate its frontiers instead of continuously expanding them. Rome could not rule an empire without limits; the further the frontiers widened and expanded, the more difficult they were to defend. Deciding that the eastern territories added to the empire by Trajan would be nearly impossible to defend Hadrian soon abandoned them, negotiated a peace with Parthia, and pulled Rome’s eastern frontier back to more defensible, manageable limits. He also secured Rome’s northern frontier by building a stone wall across all of northern Britain, known thereafter as Hadrian’s Wall.
Hadrian, Jack of all Trades
Hadrian would never be as popular an emperor as Trajan, in part because of his unwillingness to win new lands and glory for Rome through wars of expansion. Nevertheless, his policies were more beneficial for Rome in the long run than Trajan’s had been, and Hadrian’s own character made him very well suited to the office of Roman Emperor. Energetic and hardworking, Hadrian made a point of traveling to every province in his vast empire at least once over the course of his reign. This allowed him to inspect frontier defenses and provincial administration in person, and it gave millions of provincial inhabitants what was, for most of them, the once-in-a-lifetime chance to actually see a Roman Emperor in person.
Hadrian was a cultured man of many talents; a soldier, administrator, artist, architect, builder, philosopher, and even a poet. He cherished a special fondness for Greek culture, visiting numerous cities in Greece at least one during his lifetime. He loved art in all its forms, becoming perhaps the greatest art patron of all Roman emperors aside from Nero. He redesigned and rebuilt a grand temple in Rome previously destroyed by fire, dedicating it to the glory of all the Roman gods (this building, the Pantheon, remains almost perfectly intact today).