Hadrian's Wall

When and Why Was Hadrian's Wall Built?

Construction of Hadrian's wall began in 122 AD during the reign of Emperor Hadrian, and took about six years to complete.

The primary reason for the construction of Hadrian's wall was for defense or, more specifically, for establishing a boundary at the edge of the Roman empire that could be more easily defended.

Hadrian became Roman emperor in 117 AD. Up until that point, the Roman empire had been expanding its frontiers (Hadrian's predecessor, Trajan, had conquered a large amount of land in the east), but Hadrian, having been forced to deal will revolts and tribal attacks on the empire's frontiers as soon as he succeeded Trajan, recognized the need to shore up the defenses at the outer edges of Roman territory.

In many places, natural features provided much of the protection required. Unlike other frontier provinces such as Germania, which used the Danube and Rhine rivers as natural borders, Britannia had no such natural features.

On the one hand, being an island meant that any foreign invasions would have to come by sea… which would have been useful were it not for the fact that the Romans had already seen off all of the rival civilizations who could actually have mounted such a naval threat!

Although there were small-scale raids from time to time by tribes in small boats from across the Irish sea, they were more interested in plundering and returning home rather than inflicting any sort of lasting damage on the Romans by trying to take land.

Instead, by this time, the only threat to Roman-held territory in Britannia came from local tribes in the north who would attack over land.

The Roman conquest of Britannia can cause some confusion for us today. When we think of Britannia, we think of the mainland of modern-day Britain comprised of England, Scotland and Wales. So, when we hear that the Romans conquered Britannia, it is common to think that they sailed over and took control of this entire land area.

In fact, the Roman empire only ever advanced as far north as the central belt of Scotland (about half way up, just north of modern-day Glasgow).

Beyond this area lies the Scottish Highlands, a large mountainous region of over 25,000 square kilometers. This was the land of tribes and peoples such as the Picts and Caledonians.

Able to combine savage fighting techniques with the ability to melt away into the mountains (which were then considered by many in the ancient world to be eerily mysterious and unworldly), this, combined with the need to divert resources away to the rest of the empire, meant that the Romans failed to conquer a large part of Scotland.

On a side note, some historians have argued that in terms of an actual defensive instrument, Hadrian's Wall was actually far in excess of what was actually required, and that the legions stationed in Britannia could have dealt with any potential attack from the northern tribes without a wall.

They claim that the wall had more to do with portraying a symbol of Roman might and engineering ability; to show not only the northern tribes but also everyone else around the world who would hear of this mighty wall, what the Romans could do, to make them so in awe of the Romans that they would not even consider taking them on.

It is said that the wall could also have been covered in plaster and whitewashed to make it visible for miles around, further adding to its spectacular and dominating appearance.

Others also say that the construction of the wall was simply a method of giving the frontier legions something to keep them occupied. Always looking to consolidate what he had rather than try and apply already stretched resources to conquer even more land, Hadrian (perhaps wisely) decided to focus on defense rather than attack.

Stationed miles away from Rome, on the outer fringes of the known world, there was simply not much to do with Hadrian commanding them to hold the line rather than advance and attempt to conquer more territory for the glory of the empire and the Roman people.

Boredom would quickly lead to things like ill-discipline, poor motivation and possibly desertion, which meant that legions on permanent station in Britannia needed to be given something to do.

Where is Hadrian's Wall?

Hadrian ordered the construction of a wall stretching over 80 miles right across the top of modern-day England, creating a defensive barrier between the ‘civilized' world of the Roman empire and the savage, barbarian peoples of the northern extremities of the known world.

On a present-day map, Hadrian's Wall begins in Wallsend (deliberately-named because it is the end of the wall) in the east near the city of Newcastle-upon-Tyne. There are still ruins to visit today of the Roman fort of Segedunum, which was situated here at the end of Hadrian's Wall.

The wall ends just outside a small village of about 100 houses called Bowness-on-Solway, on the shore of the Solway Firth on the west coast.

Also, there can be a common misconception that Hadrian's wall marks the boundary between England and Scotland. While it did mark the boundary of the Roman empire for a large period of time, Hadrian's Wall is located entirely in England.

Because the England-Scotland border is largely diagonal while Hadrian's Wall is relatively straight across, it is difficult to say how far away the border is, but in the west it comes within a few miles while the eastern side the wall is some 60 or so miles south of the border.

How Big Was Hadrian's Wall and Who Actually Built It?

Rather than being constructed as one continuous line of stone, the building of the wall was somewhat piecemeal. Some parts were constructed of turf and then replaced with stone, while other parts such as the eastern 30 mile stretch never actually got any further than a turf ditch.

Many historians believe that circumstances changed during the construction; namely, a lack of available materials. The wall itself is not consistent in its thickness. While this may be down to the topography of the terrain in certain places, other evidence suggests that plans were altered.

R.G. Collingwood found that while the base was largely consistent, the wall itself was narrower in some places, leading him to conclude that material was in shorter supply than anticipated, which meant that the wall could not be built to the same uniform width as was originally intended.

Another myth is that slaves were used to build the wall. Although the Romans were certainly partial to using slave labor for many things, important military construction projects like this were carried out by military personnel themselves.

The building of fortifications was a common task of the legionaries, and as such they nearly always travelled with those who had the necessary skills to build them such as surveyors, masons, carpenters etc.

Stereotypical yet accurate, shifting so much heavy stone around also required the brute muscle power of the strong men of the legions!

Three legions that were stationed in Britannia are credited with the construction of Hadrian's Wall. These were II Augusta, VI Victrix, and XX Valeria Victrix, and would have comprised somewhere between around 15,000 to 18,000 men in total (Related Topic: Organization of the Roman Imperial Legion), which goes to show just how much manpower was needed to construct such a feature.

As we have seen earlier, Hadrian's Wall was not uniform along its length in terms of how wide it was, with widths varying from between around 9.5ft and 7.5ft in modern measurements. It was wide enough, however, for a soldier to walk along, keeping a constant look out for potential signs of trouble.

The height of Hadrian's Wall is even more difficult to say with any certainty, as today much of the stone has fallen down and been taken away over the centuries, so much so that the stonework is only about 4 or 5 feet high these days.

However, ancient historians such as the Benedictine monk The Venerable Bede have written that the wall would have been about 12 feet high when it was constructed, and possibly a bit higher.

This seems quite likely, as it would need to be tall enough to provide a worthwhile barrier, which a small wall that could easily be scaled would not.

Troops, Forts and Garrisons

It is easy to forget that Hadrian's Wall was not just a continuous stone wall that was built and then left to keep people out by itself. No matter how well built, given long enough the stone could be hammered away or the wall tunnelled under, so it was imperative that troops remained stationed nearby to watch for enemy activity.

The Romans took no chances with their newly-constructed wall. They built small fortifications every Roman mile (0.92 modern miles) which housed about 20-30 troops, as well as other lookout posts and larger garrison forts.

It is estimated that, during the height of its occupation in the 2nd and 3rd centuries AD, there were about 9,000 troops all told stationed at and around Hadrian's Wall, which was approximately 15% of the entire Roman army at the time.

It is difficult to acquire much reliable evidence regarding which kind of troops were stationed on and around Hadrian's Wall. It is generally thought that regiments of auxiliary infantry and cavalry drawn from the surrounding Roman provinces were the ones actually manning the wall itself, while the regular legionaries were stationed in the nearby forts, ready to spring into action should they be needed to defend against any large-scale attack.

Could Anyone Cross to the Other Side?

Designed to keep marauding tribes out, Hadrian's Wall was in fact not just one solid wall which kept people on one side and everybody else on the other. There was actually quite a lot of movement back and forth; mainly traders taking goods to buy and sell.

This movement took place through crossing points, allowing the Romans to keep a close watch on the comings and goings. Not only was this to watch the people, but was also to ensure that applicable taxes on trade goods could be levied.

Plus, of course, Roman troops needed gates to get through should they ever be ordered to advance northwards.

Hadrian's Wall After the Death of Emperor Hadrian

When Hadrian died in 138 AD his successor, Antoninus Pius, assumed a somewhat proactive approach to maintaining peace on the empire's frontiers.

Although he preferred to stay in Rome rather than travel on campaign as Hadrian and Trajan had done, he was keen to use his legions to take the fight to other peoples before they became a problem, with the added bonus of expanding the borders of Roman territory even further.

Along with suppressing revolts in Achaea and Egypt, as well as "forcing" peace on the Moors in North Africa, Antoninus Pius pushed the legions in Britannia further north in an attempt to defeat, or at least push further back, the northern tribes.

The Romans were able to advance approximately another 100 miles, building a turf ditch 40 miles long and 10 feet deep now known as the Antonine Wall.

This marked the true extent of the Roman empire as, despite a later (unsuccessful) attempt by Septimius Severus some 50 years later to conquer the north of Caledonia, the Roman empire would never extend beyond this point.

As the Roman empire declined, the legions were pulled back from Britannia, until it was abandoned by the military altogether in 410 AD. No longer serving any practical use, the wall began to fall into ruin, and the stone used in other projects such as construction (the nearby St Paul's Church in Monkwearmouth-Jarrow Abbey for instance) and road building.

Declared a UNESCO World Heritage Site in 1987, large parts of the length of Hadrian's Wall remain today, even if it is nowhere near as tall as it once was. Visitors can walk near it and go right up to the wall, and in 2003 a National Trail footpath, Hadrian's Wall Walk, was opened.

This runs the entire length of the wall from one end to the other for those wanting to combine history with exercise and fresh air, although walkers are asked to only follow the trail in summer when the ground is more firm.