Rome’s border walls were the beginning of its end.
From around 500 B.C., Rome expanded continually for six centuries, transforming itself from a small Italian city-state in a rough neighborhood into the largest empire Europe would ever know.
The emperor Trajan was an eager heir to this tradition of aggression. Between 101 and 117, he fought wars of conquest in present-day Romania, Armenia, Iran, and Iraq, and he brutally suppressed Jewish revolts. Roman coins commemorated his triumphs and conquests.
When he died in 117, his territory stretched from the Persian Gulf to Scotland. He bequeathed the empire to his adopted son—a 41-year-old Spanish senator, self-styled poet, and amateur architect named Publius Aelius Hadrianus. Faced with more territory than Rome could afford to control and under pressure from politicians and generals to follow in the footsteps of his adoptive father, the newly minted emperor—better known as Hadrian—blinked. “The first decision he made was to abandon the new provinces and cut his losses,” says biographer Anthony Birley. “Hadrian was wise to realize his predecessor had bitten off more than he could chew.”
The new emperor’s policies ran up against an army accustomed to attacking and fighting on open ground. Worse, they cut at the core of Rome’s self-image. How could an empire destined to rule the world accept that some territory was out of reach?
Hadrian may simply have recognized that Rome’s insatiable appetite was yielding diminishing returns. The most valuable provinces, like Gaul or Hadrian’s native Spain, were full of cities and farms. But some fights just weren’t worth it. “Possessing the best part of the earth and sea,” the Greek author Appian observed, the Romans have “aimed to preserve their empire by the exercise of prudence, rather than to extend their sway indefinitely over poverty-stricken and profitless tribes of barbarians.”
The army’s respect for Hadrian helped. The former soldier adopted a military-style beard, even in official portraits, a first for a Roman emperor. He spent more than half of his 21-year reign in the provinces and visiting troops on three continents. Huge stretches of territory were evacuated, and the army dug in along new, reduced frontiers. Wherever Hadrian went, walls sprang up. “He was giving a message to expansion-minded members of the empire that there were going to be no more wars of conquest,” Birley says.
By the time the restless emperor died in 138, a network of forts and roads originally intended to supply legions on the march had become a frontier stretching thousands of miles. “An encamped army, like a rampart, encloses the civilized world in a ring, from the settled areas of Aethiopia to the Phasis, and from the Euphrates in the interior to the great outermost island toward the west,” Greek orator Aelius Aristides noted proudly, not long after Hadrian’s death.
That “outermost island” was where Hadrian built the monument that bears his name, a rampart of stone and turf that cut Britain in half. Today Hadrian’s Wall is one of the best preserved, well-documented sections of Rome’s frontier. Remnants of the 73-mile barrier run through salt marshes, across green sheep pastures, and for one bleak stretch not far from downtown Newcastle, alongside a four-lane highway. Miles of it are preserved aboveground, lining crags that rise high above the rain-swept countryside.
More than a century of study has given archaeologists an unparalleled understanding of Hadrian’s Wall. The wall, perhaps designed by Hadrian himself on a visit to Britain in 122, was the ultimate expression of his attempt to define the empire’s limits.
In most places the stone wall was an intimidating 14 feet tall and 10 feet wide. Traces of a 9-foot-deep ditch running the length of the wall are still visible today. In the past few decades excavations have uncovered pits filled with stakes between ditch and wall, one more obstacle for intruders. A dedicated road helped soldiers respond to threats. Regularly spaced gates were supported by watchtowers every third of a mile.
A couple miles behind the wall, a string of forts was evenly spaced half a day’s march apart. Each fort could house between 500 and 1,000 men, capable of responding quickly to any attacks. In 1973 workers digging a drainage ditch at Vindolanda, a typical frontline fort, uncovered piles of Roman trash under a thick layer of clay. The wet layer held everything from 1,900-year-old building timbers to cloth, wooden combs, leather shoes, and dog droppings, all preserved by the oxygen-free conditions.
Digging deeper, excavators came across hundreds of fragile, wafer-thin wooden tablets covered in writing. They provide day-to-day details of life along Hadrian’s Wall: work assignments, duty rosters, supply requests, personal letters. There is even a birthday party invitation from one officer’s wife to another, the earliest surviving example of women’s handwriting in Latin.
The tablets suggest that watching over the “wretched little Britons,” as one Vindolanda writer describes the locals, was no picnic, but the fort wasn’t exactly a hardship post. Some soldiers lived with their families—dozens of children’s shoes, including baby booties, are among the footwear recovered. And the wall’s patrollers ate well: Bacon, ham, venison, chicken, oysters, apples, eggs, honey, Celtic beer, and wine were on the menu. There was even garum, a fermented fish concoction that was the Roman version of Worcestershire sauce. Homesick soldiers received care packages too. “I have sent you … socks … two pairs of sandals and two pairs of underpants,” writes one concerned correspondent.
Scholars today ask a key question that must have crossed the minds of Roman soldiers shivering through long watches in the English rain: What were they doing there in the first place? The scale of the wall and its system of ditches, ramparts, and roads suggest that the enemy could be deadly.
Yet reports from Vindolanda hardly portray a garrison under pressure. Aside from a few scattered clues—like the tombstone of luckless centurion Titus Annius, who was “killed in the war”—there are no direct references to fighting anywhere on the British frontier. The big building project to the north isn’t even mentioned. “You get a sense something’s up. Colossal amounts of supplies are being ordered,” says Andrew Birley, director of excavations at Vindolanda and Hadrian biographer Anthony Birley’s nephew. “But they don’t refer to the wall itself.”