What Was the Pax Romana? Rome's 200 Years of Peace
The Pax Romana, from 27 BCE under Augustus to 180 CE under Marcus Aurelius, was Rome's longest period of stability — its causes, its benefits, and the cracks that brought it to an end.
The Pax Romana — the Roman Peace — was the roughly 200-year period from 27 BCE to 180 CE during which the Roman world enjoyed the longest stretch of internal stability and relative tranquility in its history. It began when the Senate granted Octavian the title Augustus, “the revered one,” in January 27 BCE, formally ending the chaos of the late Republic, and it ended with the death of the philosopher-emperor Marcus Aurelius in 180 CE, after which the empire entered a long succession crisis. Across those two centuries, the armies of Rome largely stopped marching against each other, the gates of the temple of Janus were closed — a rare event — and the Mediterranean became, in the words of the poet Horace, a single Roman lake. For the broader setting, see the complete history of the Roman Empire.
The Pax Romana was not, strictly speaking, an era without war. The legions fought almost continuously on the frontiers, and the conquests of Britain, Dacia, Mesopotamia, and the Jewish revolts of 66 and 132 CE were all carried out within it. But the wars were fought on the edges of the empire, not at its heart, and the senatorial and equestrian classes, the urban plebs of Rome, and the provincial populations of the Mediterranean basin lived their lives in a degree of physical security that had never existed before and would not exist again for centuries.
The Augustan Settlement
The Pax Romana was the work of one man, Augustus (r. 27 BCE – 14 CE), and of the political settlement that he crafted to end a century of civil war. The Roman Republic, from 133 BCE onward, had been torn apart by a series of social and political conflicts that culminated in the wars of 49 to 30 BCE. By the time Octavian defeated Mark Antony and Cleopatra at the Battle of Actium in 31 BCE, the old Republic was dead in everything but name. For the long road that led there, see the fall of the Roman Republic.
Augustus gathered, gradually and carefully, all the real sources of power into his own hands: the command of the army, the control of the frontier provinces, the right to make law by senatorial decree, and the religious authority of the pontifex maximus (assumed in 12 BCE). He kept the Senate, the consuls, the tribunes, and the old magistracies in place, and the regime that resulted is called the Principate — the rule of the princeps, the first citizen. Augustus died in 14 CE, by which time the Romans regarded the new order as a deliverance. His stepson Tiberius succeeded him without incident, and the imperial succession held for the next 150 years.
Trade, Roads, and the Mediterranean Economy
The Pax Romana rested on a foundation of unprecedented economic integration. The Romans built a network of paved highways that ran from the Atlantic coast of Spain to the banks of the Euphrates. The most famous was the Appian Way, begun in 312 BCE, but there were many: the Via Egnatia across Greece, the Via Domitia through Gaul, the roads of Spain and North Africa. For a deeper look, see Roman roads. These roads allowed legions to move quickly, but they also allowed merchants, travelers, and ideas to move quickly, and they tied the empire together as no earlier state had ever been tied together.
Trade boomed. Grain from Egypt and North Africa fed the million inhabitants of Rome itself. Olive oil from Baetica (southern Spain) has been found from Hadrian’s Wall to the markets of Rome. Spices, silk, and precious stones came overland from India and China via the Red Sea. Wine from Italy, Greece, and Gaul was exported across the Mediterranean.
The Mediterranean became, in effect, a single Roman lake — Mare Nostrum, “Our Sea.” Pirate fleets, which had plagued Roman commerce in the late Republic, were swept from the sea by Pompey the Great in 67 BCE and never seriously reappeared while the empire was strong.
A Common Culture
The Pax Romana was also a period of cultural and legal integration. Latin and Greek were the two great languages of the empire, and an educated Roman could travel from the Atlantic to the Euphrates without needing a translator. The same set of Roman laws governed contracts, marriage, inheritance, and citizenship. The same imperial cult, centered on the worship of the deified Augustus and his successors, was celebrated in cities from Britain to Syria. For the religious side, see Roman religion and mythology.
The provincial cities of the empire — Lyon, Carthage, Antioch, Ephesus, Alexandria, Gades, Cirta, Londinium — were the cultural and economic engines of the Roman world. For the provincial experience, see Roman Egypt and Roman Gaul.
The emperors of the Pax Romana were, for the most part, capable and conscientious. The “Five Good Emperors” — Nerva, Trajan, Hadrian, Antoninus Pius, and Marcus Aurelius — ruled from 96 to 180 CE, and their reigns are remembered as the high point of the empire. For a tour of their reigns, see the Five Good Emperors. Marcus Aurelius, the philosopher-king, spent most of his reign on the Danube frontier fighting the Marcomanni and the Quadi, and died at Vindobona (modern Vienna) in 180 CE.
The Cracks in the Peace
The Pax Romana was not as peaceful as its name suggests. The great eruption of Vesuvius in 79 CE buried Pompeii and Herculaneum, killing thousands. A great fire destroyed much of Rome in 64 CE, in the reign of Nero. The Year of the Four Emperors in 69 CE saw the armies of the empire fight a brief but bloody civil war. The Dacian Wars of Trajan (101–106 CE) and the Jewish revolts of 66–73 CE and 132–136 CE were savage.
More important, the Pax Romana was a system that depended on a small circle of capable men to manage. The imperial succession was not, in any modern sense, hereditary; the emperor was selected by a combination of adoption, dynastic marriage, and military acclamation. When the supply of good emperors ran out — and it ran out in 180 CE, with the accession of Commodus, the unworthy son of Marcus Aurelius — the system had no way to replace them. The period from 180 to 284 CE, the so-called Crisis of the Third Century, saw the empire nearly collapse under a combination of civil war, plague, barbarian invasion, and economic disintegration. For what followed, see the Crisis of the Third Century and, eventually, the fall of the Western Roman Empire.