An outline, era by era

Pax Romana; Five Good Emperors, Hadrian's Wall (27 BCE – 180 CE)

Classical Antiquity · ~500 BCE – ~500 CE

The Pax Romana, or Roman Peace, is the name given to the long stretch from 27 BCE to 180 CE when the Roman Empire was largely free of civil war and major wars within its core lands. It began with Augustus taking sole power and ended with the death of Marcus Aurelius. Trade, roads, cities and a common legal order spread across the Mediterranean world, though the peace was never complete: frontier wars, revolts and conquests continued, and it rested on the army.

The Five Good Emperors were Nerva, Trajan, Hadrian, Antoninus Pius and Marcus Aurelius, who ruled from 96 to 180 CE. The name comes from Niccolo Machiavelli and was made famous by Edward Gibbon. Most of them chose their heirs by adoption rather than birth. Under Trajan the empire reached its greatest size. Hadrian then fixed its borders, most famously with the wall across northern Britain begun around 122 CE, which still stands in part.

Things happened, and the rest is history

  1. Augustus settles power and ends the civil wars

    Event

    What happened

    In 31 BCE Octavian defeats Mark Antony and Cleopatra at Actium and in 30 BCE takes Egypt. In January 27 BCE he hands his emergency powers back to the Senate and is given the name Augustus, together with a large province command that includes most of the legions. He keeps the outward forms of the Republic while holding the real power.

    The rest is history

    This arrangement, called the Principate, gave Rome a stable single ruler after about a century of civil wars. Augustus kept a standing army of about 28 legions, later fewer, paid from the treasury, and the Senate accepted his rule. The Altar of Augustan Peace in Rome was dedicated in 9 BCE. Augustus ruled until his death in 14 CE, and the system lasted for centuries.

    Sources

    1. PrimaryAugustus. Res Gestae Divi Augusti. Latin and Greek inscription, 14 CE, copies from Ancyra (Ankara) and elsewhere.
    2. BookGalinsky, Karl. Augustan Culture: An Interpretive Introduction. Princeton: Princeton University Press, 1996.
    3. BookSyme, Ronald. The Roman Revolution. Oxford: Clarendon Press, 1939.

  2. The year of four emperors and the Flavian recovery

    Event

    What happened

    Nero dies by suicide in 68 CE, ending the dynasty of Augustus. In 69 CE Galba, Otho, Vitellius and Vespasian each claim the throne in turn, with fighting in Italy. Vespasian, backed by the eastern and Danube legions, wins by the end of 69 CE. He rules until 79 CE and his sons Titus and Domitian follow him.

    The rest is history

    The year 69 showed that emperors could be made by armies far from Rome. Vespasian restored the finances, began the Colosseum around 70 to 72 CE and founded the Flavian dynasty. Domitian was murdered in 96 CE, which ended that line and brought the elderly senator Nerva to power. That began the run of rulers later called the Five Good Emperors.

    Sources

    1. PrimaryTacitus. Histories. Latin history, written c. 100-110 CE, Books 1-3.
    2. PrimarySuetonius. Lives of the Caesars (Galba, Otho, Vitellius, Vespasian). Latin biographies, c. 120 CE.
    3. BookMorgan, Gwyn. 69 AD: The Year of Four Emperors. Oxford: Oxford University Press, 2006.

  3. Nerva adopts Trajan

    Event

    What happened

    After Domitian is murdered in 96 CE, the Senate chooses Nerva, who has no son. In 97 CE the Praetorian Guard forces him to punish Domitian's killers, and he responds by adopting the general Trajan, then governing Upper Germany. Nerva dies in January 98 CE and Trajan succeeds without disorder.

    The rest is history

    This began the pattern of choosing the best man and adopting him, used for Trajan, Hadrian, Antoninus Pius and Marcus Aurelius. It worked partly because several of the emperors had no surviving sons. Tacitus praised the age for rare freedom to think and speak. The pattern ended in 180 CE, when Marcus Aurelius was succeeded by his natural son Commodus.

    Sources

    1. PrimaryPliny the Younger. Panegyricus. Latin speech to Trajan, 100 CE.
    2. PrimaryCassius Dio. Roman History, Books 68-69. Greek history, early 3rd century CE.
    3. BookBennett, Julian. Trajan: Optimus Princeps. London: Routledge, 1997.

  4. Trajan's conquests and the empire at its greatest size

    Event

    What happened

    Trajan conquers Dacia, in present-day Romania, in two wars, in 101 to 102 and 105 to 106 CE, and annexes the Nabataean kingdom as the province of Arabia in 106 CE. In 113 CE he begins a war against Parthia and takes Ctesiphon in 116. Revolts break out behind him, and he dies in 117 CE.

    The rest is history

    Trajan's Column in Rome, dedicated in 113 CE, shows the Dacian wars in carved scenes. Dacian gold paid for much of his building. His successor Hadrian gave up the new eastern provinces beyond the Euphrates. Most historians see this as sensible, given the revolts and the cost of holding them. Dacia stayed Roman until the 270s.

    Sources

    1. PrimaryTrajan's Column. Marble relief column, Rome, dedicated 113 CE.
    2. BookBirley, Anthony R. Hadrian: The Restless Emperor. London: Routledge, 1997.
    3. BookBennett, Julian. Trajan: Optimus Princeps. London: Routledge, 1997.

  5. Hadrian fixes the frontiers

    Event

    What happened

    Hadrian visits the provinces for much of his reign, and on a visit to Britain in 122 CE orders a wall built across the island from the Tyne to the Solway. Legionaries build it over several years, with milecastles and forts. Hadrian also strengthens the Rhine and Danube borders and the German frontier with a timber palisade.

    The rest is history

    The wall ran about 73 miles, or 117 km, and was a barrier for controlling movement and a base for troops, not a last defence. Around 142 CE Antoninus Pius pushed north and built the Antonine Wall in Scotland, but it was abandoned within a generation or so, and Hadrian's line became the frontier again. Much of it survives today and it is a World Heritage Site. Hadrian died in 138 CE.

    Sources

    1. PrimaryHistoria Augusta, Life of Hadrian. Latin biography, late 4th century CE.
    2. BookBreeze, David J. The Frontiers of Imperial Rome. Barnsley: Pen and Sword, 2011.
    3. BookBirley, Anthony R. Hadrian: The Restless Emperor. London: Routledge, 1997.

  6. Hadrian's Wall built to keep out the barbarians

    Popular belief

    The legend

    Hadrian's Wall is often said to mark the edge of the civilized world, built to hold back hordes of savage Scots and Picts. Soldiers are pictured standing on it day and night against attack.

    The rest is history

    The wall was built in the 120s CE, and the Picts are not named in Roman sources until the late 3rd century, so they did not exist as a named people then. The wall was crossed by gates at every milecastle, and was mainly for controlling trade, taxing and policing movement and watching the frontier. The Vindolanda writing tablets, wooden letters found from 1973 near the wall, show a busy military community with families, trade and ordinary supply lists, not constant war.

    Sources

    1. PrimaryVindolanda tablets. Wooden writing tablets, c. 90-120 CE, found at Vindolanda, Northumberland.
    2. BookBreeze, David J. The Frontiers of Imperial Rome. Barnsley: Pen and Sword, 2011.
    3. BookBowman, Alan K. Life and Letters on the Roman Frontier: Vindolanda and Its People. London: British Museum Press, 1994.

  7. The Ninth Legion vanished in Britain

    Popular belief

    The legend

    The Ninth Legion, Legio IX Hispana, marches into the mists of northern Britain and is wiped out, never to be seen again. Its loss is said to be why Hadrian came to Britain and built his wall.

    The rest is history

    The legion is last firmly attested at York in 108 CE, and its later fate is unknown. It may have been moved to the Rhine or the east, and some inscriptions and tiles of the Rhine area suggest this, though the evidence is debated. Nothing ties its loss to Hadrian's visit. The tale was made popular by Rosemary Sutcliff's 1954 novel The Eagle of the Ninth, and by later films.

    Sources

    1. PrimaryInscription from York recording the rebuilding of the legionary fortress by Legio IX Hispana, 108 CE. RIB 665.
    2. BookBirley, Anthony R. Hadrian: The Restless Emperor. London: Routledge, 1997.
    3. BookSutcliff, Rosemary. The Eagle of the Ninth. Oxford: Oxford University Press, 1954.

  8. Hadrian and Antinous

    Heroic tale

    The legend

    Hadrian's young companion Antinous drowns in the Nile in 130 CE. The grieving emperor weeps like a woman, so the story goes, and declares him a god. Some accounts say Antinous gave his life as a sacrifice to prolong the emperor's.

    The rest is history

    The core is documented: Antinous, from Bithynia, died in Egypt in October 130 CE, and Hadrian founded the city of Antinoopolis near the spot. He was worshipped as a god, with temples and games, and hundreds of statues of him survive. The sacrifice story appears in the later Roman sources Cassius Dio and the Historia Augusta, which also say the cause of death was uncertain. Whether it was accident, sacrifice or something else is unknown.

    Sources

    1. PrimaryCassius Dio. Roman History 69.11. Greek history, early 3rd century CE.
    2. PrimaryHistoria Augusta, Life of Hadrian 14. Latin biography, late 4th century CE.
    3. BookBirley, Anthony R. Hadrian: The Restless Emperor. London: Routledge, 1997.

  9. Marcus Aurelius, the philosopher emperor

    Heroic tale

    The legend

    Marcus Aurelius is told as the wise philosopher king, who rules justly and writes his private thoughts by lamplight in his army tent on the Danube frontier. He is held up as the ideal ruler who was never corrupted by power.

    The rest is history

    His Meditations, written in Greek in his last years, are a real private notebook of Stoic reflections, probably written during campaigns in the 170s CE. He did face a plague from about 165 CE, the Antonine Plague, and long wars against the Marcomanni and others on the Danube. The calm image is partly Gibbon's. Marcus also persecuted Christians in some places, and he handed power to his son Commodus in 180 CE, which ended the line of adoptive emperors. He died that year, probably at Vindobona or Sirmium.

    Sources

    1. PrimaryMarcus Aurelius. Meditations. Greek philosophical notebook, c. 170-180 CE.
    2. BookBirley, Anthony R. Marcus Aurelius: A Biography. London: Routledge, 1987.
    3. BookHadot, Pierre. The Inner Citadel: The Meditations of Marcus Aurelius. Cambridge, MA: Harvard University Press, 1998.

  10. Trajan and the widow's justice

    Folk tale

    The legend

    As Trajan rides out at the head of his army, a poor widow begs him to avenge her son's murder. He promises to do so when he returns, but she says he may die first. So Trajan gets down from his horse and gives judgment on the spot. In the medieval telling, Pope Gregory the Great later prays for the pagan emperor and his soul is saved.

    The rest is history

    The tale is not found in Trajan's own time. It first appears in the Middle Ages, in the 8th-century Life of Gregory the Great, and was retold by Dante in the Purgatorio. Its roots may lie in an older Roman story about a ruler stopping to hear a petitioner. Trajan did build a reputation for accessibility, and Pliny's letters show him answering provincial questions in writing. The story shows how he came to symbolise justice long after his death in 117 CE.

    Sources

    1. PrimaryDante Alighieri. Purgatorio, Canto 10. Italian poem, early 14th century.
    2. PrimaryPliny the Younger. Letters, Book 10 (correspondence with Trajan). Latin, c. 110-112 CE.
    3. BookBennett, Julian. Trajan: Optimus Princeps. London: Routledge, 1997.

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