The Antonine Wall: Roman Britain’s final frontier

Built by three legions under the command of Governor Quintus Lollius Urbicus from AD 142, the wall stretched 37 miles (or around 40,000 Roman paces) from the Firth of Forth to the Firth of Clyde. Seventeen forts punctuated its length, with smaller fortlets roughly every mile inbetween, housing a total of 6,000–7,000 soldiers. According to Professor Bill Hanson of the University of Glasgow, who specialises in Roman frontiers, “It was an enormous project. Absolutely massive – there’s no doubt it would have dominated the landscape.”

Imperial propaganda

So what led Rome’s leaders to invest such a huge amount of manpower and resources in an inhospitable enemy territory more than 1,500 miles from the imperial capital? The answer, it seems, is largely down to canny political careerism on the part of the man from whom the wall takes its name – Antoninus Pius. On becoming emperor in AD 138, the reportedly mild and sensible Antoninus had no military achievements of which to boast. “In a society in which an emperor’s power, prestige and status depended upon military prowess and ability to expand the empire, Antoninus needed an expansionist project to boost his military credentials,” says Hanson. And Britain was the ideal place to pursue a politically motivated campaign. It was familiar territory for Roman troops, while a connection to Julius Caesar, who had first invaded in 55 BC, added to its propaganda potential. However, Antoninus was cautious in his ambitions. Rather than risk taking on the Caledonian tribes to bring the entirety of Scotland under Roman control, he opted for the rather more modest goal of extending the empire’s territory 100 miles further than his predecessor, Hadrian. Antoninus’s venture paid off. He was richly rewarded back in Rome with an imperial acclamation, only the second of his tenure as emperor.

At Rough Castle, as a bitter wind buffets around us and we spot a pair of Wellington boots abandoned at the bottom of the ditch, Rome seems a long way away. But although it may have been on the furthest fringes of empire, this outpost was part of a much bigger, interconnected system. “While Britons would be subsumed into the army and shipped out to places such as Germany, likewise the Antonine Wall was staffed by auxiliary troops brought in from across the empire. That way, they were less likely to side with the locals. We know that the Sixth Cohort of Nervians, from modern-day Belgium, were stationed at Rough Castle, and others living on the wall hailed from as far off as Syria and Morocco.”

Life on the wall

With no written sources in existence about everyday life on the wall, the best evidence to hand is archaeological. Since the early 20th century, digs have turned up a wealth of metalwork, bronze work, coins and brooches, and plenty of pottery – “stuff you usually find” at Roman sites, Hanson says, casually listing the objects with the familiarity of someone who has found plenty such artefacts over the years.

Today, you can walk around the former site of the garrison’s barracks, regimental bathhouse, granary and commander’s residence. You can also trace sections of the military way, the Roman road running along the south of the wall to allow for the easy transportation of troops and supplies.

Unlike the stone-built Hadrian’s Wall (where ramparts still remain visible for visitors to scramble over today) the Antonine Wall was only ever a turf rampart on a stone base. Although it is thought to have risen as high as an intimidating 12ft, and was 14ft wide at points, 1,800 years of erosion by Scottish weather now mean that even the best preserved section of rampart (found at Rough Castle) is little more than a grass-covered hump. Yet the wall was no mere mound of mud. To the north of the ramparts was a massive ditch. Up to 40ft wide and 12ft deep, it was far bigger than that at Hadrian’s Wall, and perilously steep. The best surviving sections can now be found at nearby Watling Lodge. Walking along the base of the ditch today gives you a sense of the impossibility of scaling it. Even after centuries of weathering, it still looms far above our heads.

The forts held hundreds of men, an attraction for merchants, traders, prostitutes and tavern keepers

And the defences didn’t stop there. Sloping up towards the ditch we encounter one of Rough Castle’s strangest sights: a series of oval-shaped pits, perfectly aligned in tight, alternating rows. These, Hanson tells me, are lilia. While their floral-inspired name may sound innocuous, these lilia were anything but – they were deadly mantraps. “You dug a hole, put a sharpened stake in the bottom and then covered it over so it was hidden,” Hanson says. “Or you could fill them with thorn bushes, to act as a sort of natural barbed wire. Setting the pits in an alternating pattern meant that it was nigh on impossible to run up the slope without hitting one – anyone trying to sneak up on the fort would soon find themselves in trouble. When you add these to rampart and ditch, you can see that the wall certainly wouldn’t be crossed in a hurry.”

Shock and awe

Urbicus’s troops didn’t only use physical defences to deter attacks, but also scare tactics and intimidation. Placed along the wall were intricately carved distance markers, some of which can be seen at Glasgow’s Hunterian Museum. As well as recording the construction undertaken by various legions, these stones were decorated with violent images of the subjugation of Scots. They were brightly painted, and even used a specific shade of red to depict blood in images of beheaded Caledonians and vicious Roman eagles with blood-stained beaks. These gory carvings were clear statements of Roman domination, easily understood by those unable to read the Latin inscriptions.

These defences suggest the Romans took the threat of attack by Caledonian tribes seriously. “I think the Romans did perceive there to be a genuine threat from the north,” says Hanson. “It’s possible that there was a backlash to the installation of a hard border that cut through existing social boundaries. Further forts were added to the original plan for the wall, which may well have been a knee-jerk reaction to that local backlash.”

However, the relationship between local people and their Roman occupiers was not wholly antagonistic. “A whole range of different techniques were used to keep local people onside, from military intervention to political arrangements,” says Hanson. Excavations at indigenous Scottish broch sites have uncovered Roman materials, suggesting that trade took place between the two peoples.

Even along the wall itself, the lines between Romans and locals were far from clear cut. “People tend to forget that these forts were not solely military in nature,” says Hanson. “The fact that they held hundreds of men with money was an attraction for merchants, traders, prostitutes and tavern keepers, so it was inevitable that small communities would have sprung up around them. At Croy Hill, for example, we know there was a civilian settlement on one side, and farming and a pottery kiln on the other.”

As more archaeological evidence emerges, there’s increasing evidence that, although Roman soldiers weren’t allowed to marry until the third century, some men had partners and families who lived in the forts or nearby. At Bar Hill, for instance, children’s leather shoes have been discovered.

Less than 20 years after construction had begun, however, the wall was abandoned – despite the huge investment of money and men funnelled into Antoninus’s grand expansion project. This was most likely because of the overstretched resources of the Roman army, which was simultaneously trying to operate troublesome campaigns elsewhere in the empire. Unable, or unwilling, to maintain the frontier, the auxiliaries fell back to the more secure boundary of Hadrian’s Wall.

The distance stones were buried and the forts demolished, but the wall and ditch were left as they were, to become enduring features of the Scottish landscape. Even today, they make for an impressive sight.

Roman forts: 3 more places to explore

Hunterian Museum, Glasgow

Where artefacts from the Antonine Wall can be found

Alongside its anatomy and zoology displays, the Hunterian is home to a permanent exhibition on the story of the wall, from its construction and habitation to its archaeological rediscovery. Many artefacts uncovered along the wall are on display here. As well as the distance slabs, there are everyday items such as a bronze lamp, gaming board, leather tent and the children's shoes found at Bar Hill fort. Find out more

Vindolanda, Northumberland

Where life in a Roman garrison was recorded for posterity

Occupied from c85–370 AD, Vindolanda is one of the most impressive forts along Hadrian's Wall. The extensive remains of the garrison are still being explored – visit between April and September and you may well see archaeologists at work. It's here that perhaps the best evidence of everyday life in Roman Britain was uncovered: the Vindolanda tablets. These ink-scrawled wooden fragments are an unparalleled record of life at the Roman garrison, and even include a birthday party invite dating back to AD 100. Find out more

Isca Augusta

Where a legion had its HQ

Located in the village of Caerleon in south Wales, this legionary fortress was one of Britain's three major Roman military headquarters, along with York and Chester. Home to the Second Augustan Legion, it was founded around AD 75, and remained a military base for expeditions to take on the warlike Silures people over the next 200 years. Caerleon is also home to the impressive remains of Britain's largest Roman amphitheatre (once big enough to seat a 5,000-strong legion), and the National Roman Legion Museum (closed for repairs until August 2019). Find out more

Professor Bill Hanson of the University of Glasgow specialises in the history and archaeology of Roman frontiers.

Words by Ellie Cawthorne.

This article was first published in the January 2019 edition of BBC History Magazine