Who Were the ‘Five Good Emperors’ of Ancient Rome?

Throughout its long and eventful history, many emperors ruled the Roman Empire. Some of them failed to live up to the task. Others were simply adequate or left a divisive legacy. A few Roman emperors, however, not only ruled efficiently, they also expanded the Empire’s borders and influence, solidifying the power of Rome. Probably the most famous of them all are the so-called Five Good Emperors — the distinguished quintet that reigned between the first and second centuries CE. Their names — Nerva, Trajan, Hadrian, Antoninus Pius, and Marcus Aurelius — have been celebrated, past and present.

At the start of their reigns, Rome was in danger of another civil war. However, under their tenure, the Empire became the world’s undisputed superpower, whose influence and might was unparalleled. Yet, while their rule brought Rome to its apex, it was also during this period that the first cracks began to emerge in the Empire’s fabric. The Roman Empire would last for centuries, but it would never again attain the stability and power it held during the reign of the Five Good Emperors.

The reign of the Five Good Emperors is also known as the Nerva-Antonine dynasty. But theirs was not a traditional bloodline. From Nerva to Marcus Aurelius, rulers were not chosen based on blood but picked because of their capabilities. Nerva took the purple following the assassination of the last Flavian emperor, while all the others were adopted heirs. The Five set a precedent that would later become a trend, particularly during the chaotic Third Century Crisis.

Merit, not blood, may have been their principal formula for success. Not constrained by family connections (and the court intrigues that came with the package), the five emperors could focus on governing. Their effective rule consolidated the imperial administration and the economy, allowing for a series of highly effective campaigns that extended the Roman Empire to its greatest limits. Roman culture and law also saw significant improvements. Furthermore, the emperors commissioned a series of building projects to immortalize their achievements, reshaping the Empire’s urban and rural landscape.

Although the reforms of the Five Good Emperors brought a period of unprecedented prosperity and power, the centralization of the state, and the increased power of Roman emperors undermined the existing “dual control” system. The Roman Senate lost part of its authority, its ranks filling with the emperor’s favorites, handpicked by the monarch. This change did not seem drastic as long as the emperor himself remained competent and energetic. But in the hands of an inadequate and weak ruler, the system could (and did) backfire, undermining the state’s stability and its defenses.

Taking the purple in 96 CE, the first of the Five Good Emperors – Nerva – was a compromise candidate. The assassination of his predecessor, Domitian, brought the Flavian dynasty to an abrupt end, leaving the Empire once again on the brink of a civil war. To avoid chaos, a replacement had to be found quickly. At first, Nerva seemed an unusual choice. Sixty-six years old and childless, Nerva could hardly start a new dynasty. Yet, he was a safe bet, because he satisfied both the pro and anti-Domitian factions. Besides, Nerva had political experience and had held high positions under Nero and the Flavian emperors.

During his brief reign, Nerva tried his best to stabilize the Empire. The senators, who had been harshly persecuted in the later years of Domitian’s reign, were pardoned, and their possessions were returned. Aware of the troubles faced by the common folk, Nerva introduced several measures to improve their economic situation. The emperor paid particular attention to the poor, to whom he granted land acquired from wealthy landlords. He also reduced or abolished numerous taxes, giving privileges to the inhabitants of the provinces. The most important of those taxes was the Fiscus Iudaicus — an additional tax that all the Jewish subjects had to pay.

Nerva’s economic reforms improved the lives of the populace. However, his expenses also strained the Roman finances. Although his policies improved the emperor’s standing among the Senate and the Roman people, Nerva’s reluctance (or refusal) to punish Domitian’s assassins caused discontent among the imperial soldiers. Not satisfied with their monetary rewards, the Praetorians laid siege to the imperial palace and took the emperor hostage.

Nerva left unharmed, but his authority suffered a dramatic blow. Besides punishing his predecessor’s murderers and deifying Domitian, Nerva also announced the adoption of Trajan, and he named him his successor. The stage was set for the reigns of the adopted Roman emperors.

Following Nerva’s death in 98 CE, Trajan took the reins of the Empire. Born in Spain, Trajan was the first Roman emperor who came from outside Italy. However, it would be wrong to see him as a mere provincial, since Trajan’s family traced their origins to the Apennine Peninsula. Contrary to popular belief, Nerva did not choose Trajan because of his extraordinary abilities. Faced with a major crisis, the emperor required the support of a powerful figure who could restore his damaged reputation. Fortunately, Trajan was such a man, and more.

At the time of his adoption by Nerva, Trajan was a successful military commander, which made him popular with the army. Thus, it is not surprising that Trajan’s reign saw several large-scale military campaigns that led to the extension of the imperial borders. Early in his reign, Trajan annexed the Nabatean Kingdom, spreading the imperial influence into Arabia. Then he crossed the Danube, conquering Dacia, a region rich in gold. Trajan was one of the few Roman emperors to avoid Crassus’ curse. His successful campaign against the great Roman nemesis — Persia — gained him the provinces of Armenia and Mesopotamia, and Roman influence reached the Persian Gulf.

Trajan was also successful in domestic affairs. Upon his accession, the emperor continued Nerva’s policy of cooperation with the Senate. At the same time, Trajan slowly pushed for increased centralization and greater personal powers. Trajan was the first ruler to appoint his own trusted men, (such as Pliny the Younger) as provincial governors and high imperial officials.

Trajan also paid particular attention to the embellishment of his growing Empire. Trajan’s reign was characterized by an ambitious building program, which reshaped both the capital and the provinces. Trajan’s greatest monument was the new Forum in Rome, which included the splendid column that commemorates his victories. In the capital, Trajan also commissioned a massive bathing complex, as well as new markets. Those structures remained a potent reminder of the emperor’s power centuries later.

For his numerous accomplishments, the Senate officially declared Trajan optimus princeps, meaning “the best ruler.” It is hard to say what else this ambitious emperor might have achieved had he lived longer. However, in 117 CE, on his way home from the East, Emperor Trajan fell ill and died. Trajan’s last achievement was a peaceful transfer of power. On his deathbed, he adopted Hadrian, who proved to be a worthy successor of the “best emperor.”

Like Trajan, Hadrian came from Spain. He was also a high-ranking military officer, who accompanied Trajan on his many campaigns. While Hadrian was a logical choice for Trajan, it appears that this prominent aristocrat also took the purple with the help of the late emperor’s powerful wife, Plotina. It was Plotina who claimed that Trajan nominated Hadrian as the next Roman emperor on his deathbed.

The army and the Senate approved of Trajan’s last wish. Yet, the death of four leading senators following the accession suggests that Hadrian encountered opposition. The Senate never forgave the emperor for this violent act. Furthermore, the senators disliked his reversal of imperial policy. Hadrian halted Trajan’s offensive military campaign and abandoned most of the territories taken by the emperor. For the first time since the inception of the Empire (and the Republic), Rome was in retreat. While the Senate considered withdrawal un-Roman, Hadrian’s decision had a practical reason.

Hadrian realized that most of the territory conquered by Trajan was too difficult to hold or simply unprofitable. Instead of further conquest, Hadrian established a permanent frontier that incorporated the Rhine and Danube in the West, and the Tigris and Euphrates in the East, into an easily defensible border. Walls, towers, forts, and fortified roads, manned by Roman legionaries, protected the Roman Empire and its subjects from external threats. The remains of Hadrian’s most enduring accomplishment, the stone wall bearing his name, still stands in its entire length, in the north of England.

Hadrian was not a soldier-emperor, but this does not mean that he was not an active one. In his 21-year long reign, the emperor spent more than a third of his time outside of Italy.  He traveled along the vast frontier, inspecting his troops, personally overseeing construction projects, and meeting with the provincial authorities. Yet, the emperor did not forget the Roman heartland. An active builder and a heartfelt Philhellene, Hadrian commissioned an extensive building program, in both the capital and the provinces. The lavish imperial villa in Tivoli, and the Pantheon, initially commissioned by Marcus Agrippa, and rebuilt by Hadrian, are among his best-known architectural works.

Hadrian’s reign was relatively peaceful, apart from the Jewish revolt, which lasted from 132 to 135 CE, and resulted in the crushing defeat of the Jews in the East and the almost complete erasure of  Jewish heritage from the region. Before he died in 138 CE, 62-year old Hadrian could boast of the fourth longest reign in imperial history. The emperor was interred in the mausoleum bearing his name, which still stands in the center of Rome.

Like Trajan, Hadrian chose his successor on his deathbed, thus continuing the adoptive heir tradition of the Five Good Emperors. However, this time, he followed the script with a twist. Antoninus Pius was to be the next Roman emperor, but Hadrian had also already chosen Antoninus’ successor: Marcus Aurelius. Born to a senatorial family, Antoninus Pius was a high-ranking official during Hadrian’s reign. Upon his accession, Antoninus adopted the moniker Pius, either because he had compelled the hostile Senate to deify his adoptive father, or because he spared the senators sentenced to death by Hadrian.

Antoninus’ reign was one of the rare moments of peace in Roman imperial history. The emperor’s only significant military venture was the invasion of southern Scotland, which resulted in the erection of a new defensive wall bearing Antoninus’ name. The new territory was barren and poor. The probable aim of the campaign was to gain a triumph, which could further bolster Antoninus’ standing, especially among the military.

Like the other Five Good Emperors, Antoninus commissioned several large-scale building projects. He also promoted the arts and sciences, continuing Hadrian’s work. Furthermore, the emperor continued centralizing the state, filling administrative positions with his favorites. As a result, the Empire’s prestige continued to grow. Interestingly, it was during Antoninus’ reign (or that of his successor) that a Roman embassy visited China for the first time. At the same time, diplomatic relations were strengthened with the Indian Kingdoms, including the powerful Kushan Empire.

Antoninus’ peaceful and long reign bolstered the imperial economy. Although a vast sum was spent on building projects, including several aqueducts, both in Rome and across the Empire, Antoninus was able to fill the imperial coffers leaving his successor a large surplus in the treasury. The emperor also introduced several legal reforms, including the enfranchisement of freed slaves. Antoninus Pius was one of the few emperors who behaved amiably towards the growing Christian sect. Under his laws, Christians could not be executed without a fair and just trial. Antoninus Pius died of illness in 161 CE, and according to Hadrian’s wishes, the emperor was succeeded by his adoptive sons Marcus Aurelius and Lucius Verus.

Although Marcus Aurelius is one of the most well-known Roman emperors, we should not forget that he did not rule alone. After the death of his adoptive father Antoninus Pius, Marcus inherited the Empire together with his adoptive brother Lucius Verus. The Senate had initially planned to offer the throne to Marcus alone. The emperor, however, was respectful of Hadrian’s wishes and refused to take the purple until his adoptive brother was recognized as co-ruler. Thus, the joint rule of Marcus Aurelius and Lucius Verus became the first instance of a joint reign in Roman history. Shared power would become increasingly common in the following centuries.

This new joint rule proved a good strategy. Upon the accession of the two Roman emperors, the Empire was attacked by its eternal nemesis, Persia. While Marcus remained in the capital, Lucius Verus left for the East, where he took personal command of the legions. Not only did he defeat Persia, he also sacked the Parthian capital Ctesiphon. Yet, the triumph contained the seeds of tragedy. The soldiers returning from the East brought with them an invisible enemy — the plague — a sickness that ravaged the Empire, and decimated its population and economy for more than a decade. Lucius Verus died in 169 CE, falling victim to the deadly pestilence.

Marcus Aurelius, the emperor who preferred intellectual pursuits over warfare, was now the sole emperor of Rome. To facilitate the administration, Marcus began promoting both army officers and civilian administrators on the basis of merit and ability rather than birth and class. Soon, the philosopher emperor, the fervent follower of the Stoic teachings and the author of Meditations, would have to confront the largest threat that Rome had encountered in centuries.

In 166 CE, barbarians breached the Danubian frontier, advancing deep into the imperial heartland, threatening Italy for the first time in centuries. At a bloody cost the Roman army was able to repel the invaders. It was during this troubled period that Marcus Aurelius began persecuting Christians, believing that the rapidly growing sect was responsible for the tribulations of the Empire. Marcus Aurelius would spend the rest of his reign on the frontier fighting against the barbarians. It was on the frontier that he died in 180 CE.

The death of Marcus Aurelius in the military camp on the Danube symbolically marked the end of the era of the Five Good Emperors. Once again, the emperor was able to organize a peaceful transfer of power. However, his son Commodus was unable to live up to the high standards established by his workaholic father. Commodus’ rule, marred by controversies and scandals, would expose all the weaknesses of the system established by the Five.

The centralization of the Empire and the increase of the emperor’s authority produced great results when a capable and determined ruler occupied the throne. Commodus, however, was not such a man. Although most of his transgressions were inflated by historians hostile to the regime, Commodus was not ready to rule. An absolutist and a showman, Commodus lacked the diplomatic skills of his predecessors, as well as their military capabilities, and skill at governing. In the end, his open hostility to the Senate and his arrogance proved to be his undoing.

The death of Commodus in a palace coup signified not only the end of stability, it also marked the beginning of a new era — a period when Roman emperors completely ignored the Senate and increased the power of the army. The civil wars that followed plunged the Empire into a chaos never seen before, but they also transformed Rome into a powerful absolutist fourth-century state, laying the foundations for its survival in the East for centuries to come.