On a fortified hill in Scotland some 1,900 years ago, a Roman army attacked local warriors by hurling lead bullets from slings that had nearly the stopping power of a modern .44 magnum handgun, according to recent experiments.

The assault seems to have been deadly effective, for the local warriors were armed only with swords and other simple weapons, says John Reid, a researcher at the Trimontium Trust and one of the co-directors of the archaeological fieldwork at Burnswark, south of Edinburgh. “We’re fairly sure that the natives on top of the hill weren’t allowed to survive.”

But Burnswark was just the opening salvo in a war against the restive tribes living north of Hadrian’s Wall. Despite their superior weaponry, Roman soldiers seem to have gotten bogged down in Scotland as they fought a tough, resourceful enemy capable of melting away into the hills and marshes. Less than two decades after the Romans attacked Burnswark and occupied part of Scotland’s lowlands, they retreated south to Hadrian’s Wall. “This is beginning to look like Rome’s Afghanistan,” Reid says.

View Images Roman soldiers armed with slings used these lead bullets to mow down foes. A skilled slinger could hit a target smaller than a person from 130 yards away. Photograph by John Reid

Reid and colleague Andrew Nicholson, an archaeologist at the Dumfries and Galloway Council, began studying Burnswark five years ago, hoping to uncover new clues to the events that unfolded at the site, which includes remains of two Roman camps. At the time, Scottish archaeologists were divided in their interpretations of the site. Some thought a Roman army had used Burnswark as an ancient firing range and training camp, while other researchers regarded the hill fort as the scene of a lengthy siege.

To clarify the picture, Reid and Nicholson decided to scour Burnswark for traces of ancient Roman ammunition. American archaeologists had used metal detectors successfully at the site of the Battle of Little Bighorn to locate buried bullets and shells and map the combatants’ movements across the battlefield. So Reid and Nicholson decided to try something similar at Burnswark. As a first step, the researchers learned to calibrate a metal detector so that it could distinguish the lead in an ancient Roman sling bullet from other metal artifacts buried at the site.

Trained metal detectorists then combed Burnswark’s hillsides and summit, producing more than 2,700 hits that Nicholson carefully recorded and mapped. Then the team ground-truthed the findings by digging five small trenches. The excavations revealed more than 400 Roman sling bullets right where the metal detectors indicated, as well as two spherical sandstone missiles known as ballista balls. The results suggested that 94 percent of the metal detector hits were in fact Roman bullets.

View Images Archaeologists discovered two spherical sandstone missiles known as ballista balls that were fired by Roman artillery. Photograph by John Reid

Impressed, the team began analysing the locations of the metal detector hits to better understand what had happened. They discovered a concentration of lead bullets across the entire 500-yard-long southern rampart of the Scottish hill fort, directly above one of the Roman camps. “This is just what we would expect from a besieging assault,” notes Reid. A second, smaller concentration lay to the north, along what may have been the defenders’ failed escape route.

The Roman slingers would have exacted a heavy toll. Recent experiments conducted in Germany showed that a 50-gram Roman bullet hurled by a trained slinger has only slightly less stopping power than a .44 magnum cartridge fired from a handgun. Other tests revealed that a trained slinger could hit a target smaller than a human being from 130 yards away. “That’s exactly the distance from the front rampart of the south [Roman] camp to the front rampart of the hill fort,” Reid noted.

Terror Tactics

The Romans also employed a previously unknown form of psychological warfare to terrify the Scots and undermine their resistance. While examining the bullets, Reid and Nicholson noticed small holes deliberately made in nearly 10 percent of the ammunition. Puzzled, the team cast replicas, and asked an experienced slinger to test them. The bullets with holes made “a weird banshee-like wail,” says Nicholson. “So you are getting these unworldly, unnatural sounds that you have never heard before, and people are falling over on either side of you.”

Comparative isotopic studies of bullets from Burnswark and from other well-dated sites suggests that the bloody assault took place around A.D.140, early in the reign of the Roman emperor Antoninus Pius. “He was a new emperor with a need for a military victory somewhere,” says Reid. By striking with exemplary violence at Burnswark, the emperor may have hoped to claim a quick success and subdue difficult tribes along its northern frontier.