What was the Pax Romana?

A peace with a start date

Peace was Augustus’s great selling point, after twenty years of civil war. In his own record of his reign he points to the gates of the temple of Janus Quirinus in the Forum, shut only when Rome was at peace on land and sea. Before he was born they had been closed twice in the city’s whole history. Under him, he says, the Senate ordered them closed three times (Res Gestae 13).

In 13 BC the Senate voted him an Altar of Augustan Peace, the Ara Pacis Augustae, dedicated in 9 BC. On its marble friezes his family walks in procession. Pieced back together from fragments, it stands today in a museum beside the Tiber.

What the Romans meant by it

Romans rarely used the phrase. The philosopher Seneca speaks of the peoples at the point where the Roman peace stops, the Germans and the wandering tribes along the Danube (On Providence 4.14). Pliny the Elder praised the boundless majesty of the Roman peace, which let people, plants and medicines travel between the ends of the earth (Natural History 27.3).

The modern term is a historian’s label. Most put its start in 27 BC, when Octavian became Augustus, and its end in AD 180, when Marcus Aurelius died in camp on the Danube. That makes about 207 years.

Peaceful for whom?

Peace meant something precise: no war between Romans across the whole empire, and no enemy army deep inside it. The legions, between twenty-five and thirty of them, stood on the frontiers. In Gaul, Spain or Greece many people lived whole lifetimes without seeing a battle. Elsewhere the record is bloody:

• AD 9. Three legions are destroyed in Germany’s Teutoburg Forest.
• AD 60–61. Boudica’s revolt in Britain. Tacitus says some 70,000 Roman citizens and allies died before it was crushed (Annals 14.33).
• AD 66–73. The Jewish War, and in 70 the destruction of the Temple in Jerusalem.
• AD 69. A year of civil war and four emperors, with the temple of Jupiter on the Capitol burned.
• AD 132–135. The Bar Kokhba revolt in Judaea, put down with enormous slaughter.
• AD 166–180. Marcus Aurelius’s long wars on the Danube, while a plague swept the empire.

“They make a solitude and call it peace”

The sharpest verdict on the Roman peace came from a Roman. Tacitus, a senator, wrote the life of his father-in-law Agricola, the governor who marched into Scotland. Before the battle of Mons Graupius, around AD 83, he gives the Caledonian chief Calgacus a speech to his warriors:

To robbery, slaughter, plunder, they give the lying name of empire; they make a solitude and call it peace.

In Latin the last words are ubi solitudinem faciunt, pacem appellant, often rendered “they make a desert and call it peace.” The speech is Tacitus’s own invention, as ancient historians’ speeches usually were. He was just as dry about the Britons who took up Roman ways: the toga, porticoes, baths and elegant banquets. They called it civilization, he says, when it was part of their slavery (Agricola 21).

How it ended, and what it left

Marcus Aurelius left the throne to his son Commodus, and Cassius Dio, a senator who lived through what came next, wrote that history now descended “from a kingdom of gold to one of iron and rust.” In 1776 Edward Gibbon called the years from 96 to 180 the happiest in human history. The idea outlived Rome. Victorian Britain spoke of a Pax Britannica, and after 1945 people spoke of a Pax Americana: each a peace kept by the strongest power of its day.