Romans occupied and controlled a large southern swath of the island of Great Britain as they expanded their empire. How far north, I wondered, did they extend their empire here before it began to contract? What was their high-water mark?
The Romans arrived on Britain in the year 43 and would remain as a ruling presence until 410. Hadrian’s Wall served as a de facto boundary for much of that time, however the Roman Empire extended farther north for at least a generation as I’ll explore further. Nonetheless, I started my northernmost quest with Hadrian’s Wall because of its durability. What began in 122 at the behest of the Roman emperor Hadrian would serve as a defensive fortification for the remainder of the Roman occupation. Its stonework was so well-constructed that much of the wall remains today and can be observed via the Hadrian’s Wall Path
SOURCE: Flickr via Creative Commons Attribution 2.0 Generic (CC BY 2.0) license
The Romans chose a route that reduced construction requirements, following a natural narrowing of Great Britain between the current towns of Bowness-on-Solway on the Solway Firth and Wallsend on the River Tyne (approximate route map on modern roads). Wallsend, in fact, derives its name from Hadrian’s Wall. It was quite literally the Wall’s End.
Hadrian’s Wall may have been as much a demonstration of might and power as an actual physical military deterrent along its seventy-three miles. It likely would not have halted a determined, advancing army. Rather, it was a line-in-the-sand. It served as a means to control the movement of people and goods into and out of the empire. It wasn’t a strict border per se where "enemy" territory began immediately past the wall. Roman influence would have seeped any number of miles further into the countryside. It would have been at least as porous as walled portions of the border between modern Mexico and the United States, and maybe more since they didn’t have the luxury of surveillance cameras and four-wheel drives.
Brocolitia (alternately Procolita or Brocolita) was the northernmost fortification along Hadrian’s wall, located near what is now the settlement of Carrawburgh in Northumberland. Outline ruins of the the fort and some nearby temple complexes are still visible.
The northernmost part of the wall was located a mile farther east at Mile Castle 30. Google Maps satellite view captures it clearly. This corner would have been the northernmost reach of the Roman Empire on Great Britain for much of it presence.
The Romans built a second wall, this one about a hundred miles north of Hadrian’s Wall. Antoninus Pius, the emperor who came to power after Hadrian died, pushed Roman control farther north into Britain. Construction of the Antonine Wall began in 142. This one had a stone base layered with piled earth and topped with turf.
Once again they used topography to their advantage and selected the shortest available distance to build across, from modern Old Kilpatrick on the Firth of Clyde to Carriden on the Firth of Forth (approximate route map on modern roads). They chose well. This isthmus required a wall only thirty-nine miles long. As described by Historic Scotland,
For much of its length it utilised the high ground along the southern edge of the central valley. This valley is formed by the River Carron, flowing eastward into the Forth, and the River Kelvin, a tributary of the Clyde in the west. Together, these rivers helped to create a boggy foreground to the Wall before the land rose up to the Campsie Fells to the north.
The Antonine Wall was more properly an earthwork as opposed to the stone edifice farther south. It would have served as an imposing structure nonetheless and a manifestation of Roman power. However little evidence remains today because the Romans used an impermanent construction technique. Much of it has eroded away.
The Romans overextended themselves when they moved their boundary up to the Antonine Wall. They never managed to subjugate the Caledonians who constantly harassed them. They retreated back to Hadrian’s Wall about twenty years later, circa 160. A later emperor, Septimius Severus ordered the re-establishment of the Antonine Wall in 208 but that lasted only a few years. The Romans decided it was easier to let the Brythonic tribes serve as a buffer between themselves and Caledonia rather than continue battling. Hadrian’s Wall served as the northern boundary for the remainder of the Roman era.
I found a couple of candidates for the northernmost point along the Antonine Wall. The first one was actually located slightly outside of the wall by about three-quarters of a mile, a fort known as Camelon. The Romans built this originally as a far northern outpost a couple of decades after the construction of Hadrian’s Wall. Romans reoccupied Camelon upon the construction of the Antonine Wall immediately to its south.
The second candidate was Carriden at the eastern terminus of the Antonine Wall. I compared the latitude of both locations. Camelon was 56.008° north, and Carriden was 56.012° north. Thus, by my calculations and by the narrowest of margins — a few hundred feet — Carriden beat Camelon to claim the northernmost point.
Did the Roman empire extend even farther into Great Britain? I didn’t have time to continue my investigation although I imagine it would have been a bit more ephemeral. Perhaps an educated member of the 12MC audience could enlighten us.
I’d love to spend a few weeks on a narrowboat traveling through the canals and inland waterways of Great Britain. There are literally thousands of miles of publicly-accessible routes available with much of it interconnected into a single system, allowing one to experience the countryside at four miles per hour.
While I’m sure I’d be completely content as I puttered through the British countryside, I’d certainly point a course towards the extremes and the oddities. Water doesn’t necessarily flow where man may want it to go. It has to be channeled, corralled and coaxed to form a suitable transportation network. Engineers and designers came up with some rather ingenious solutions from the late 18th Century through the middle of the 19th Century in those early years of the industrial revolution.
Does a hillside block the intended watercourse? No problem. Build a tunnel.
I had a difficult time finding a visible canal tunnel entrance from the images available on Google Street View. In general, canals are dug from the surrounding landscape so they sink below eye level. They tend to have right-of-ways on either side that becomes naturally protected spaces for trees and other vegetation. It’s easy to spot a canal running through the countryside by searching for a tell-tale line of trees. Getting a clear shot of a canal as it enters a tunnel from Street View imagery however is a completely different story.
The one shown here is known at the Dudley Tunnel and it remains submerged for about 1.75 miles. This forms part of the Dudley Canal in the West Midlands and it was used originally to transport limestone. This entrance happens to be located right by the Dudley Canal Trust which offers underground boat trips into the tunnels and over to the limestone caverns.
Imagine the importance of these inland waterways of the 19th Century especially in the days before the ubiquitous railroad. Certainly greater tonnage could be floated through the countryside than pulled by horse or ox across abysmally rutted roads and muddy paths. I suppose I shouldn’t be surprised to see canals that resemble modern road networks, as that’s the purpose they served during their prominence.
Construction engineers could design bridges — or aqueducts — at the intersection of canals where elevations differed. I found this example not far from Dudley as I searched for canal tunnels. I couldn’t get a clear image of the tunnel (open the map and it can be found immediately to the south-southwest) but I did find this nice bridge. Here the Netherton Tunnel Branch Canal passes beneath the Old Birmingham Canal Navigations (BCN) Main Line at Tividale Aqueduct.
Exceptional aqueducts existed at valley crossings. Designers sometimes chose to cut a path directly above the valley rather than step a canal down to the valley floor and then step it back up with a system of locks. An aqueduct is more difficult from an engineering standpoint but transportation time savings would be considerable.
Pontcysyllte Aqueduct in Wales is particularly dramatic, carrying the Llangollen Canal over a valley formed by the River Dee. This cast iron structure spans nearly a quarter of a mile while carrying boats 125 feet above the valley floor. Google Street View captured this well. I can see four boats crossing in succession. The though of carrying what is essentially a river across this gap is truly remarkable. Perhaps that is why this 1805 achievement is a UNESCO World Heritage Site:
Situated in north-eastern Wales, the 18 kilometre long Pontcysyllte Aqueduct and Canal is a feat of civil engineering of the Industrial Revolution, completed in the early years of the 19th century. Covering a difficult geographical setting, the building of the canal required substantial, bold civil engineering solutions, especially as it was built without using locks. The aqueduct is a pioneering masterpiece of engineering and monumental metal architecture, conceived by the celebrated civil engineer Thomas Telford. The use of both cast and wrought iron in the aqueduct enabled the construction of arches that were light and strong, producing an overall effect that is both monumental and elegant…
Lifts and Wheels
I have nothing against canal locks. I rather enjoy them as a matter of fact, both modern and antique. However they’re simply too common. Tunnels and Aqueducts are great too, however, let’s get to some even more unusual structures that can be experienced on the inland waterways of Britain.
I couldn’t find a decent angle on the maps websites so I’ve borrowed an image from Flickr. This shows the Anderton Boat Lift in Cheshire (see map). A boat enters the lift. Counterweights composed of water-filled caissons move vessels between the River Weaver (up) and the Trent & Mersey Canal (down). The elevation difference between the two waterways is about fifty feet.
Only one other working boat lift exists in Britain and it’s of recent vintage: the Falkirk Wheel in Scotland (see map).
I’d love to visit someday but I’ll have to satisfy my curiosity with YouTube for now. It’s also a lot easier to let the video demonstrate how this thing works instead of trying to explain it. The Falkirk Wheel is a rotating lift rather than an elevator-style lift. It is used to connect the Forth and Clyde Canal with the Union Canal, replacing eleven traditional locks over a nearly eighty foot elevation difference.
The Falkirk Wheel arrived more than a century after the heyday of industrial revolution canal building. It opened in 2002. This recent vintage seems somewhat mystifying since many other options are available for cargo transport. It seems to exist primarily for tourism and recreation.
Are other options available? Why yes, there’s always the inclined plane.
Great Britain no longer has any functioning inclined planes along its inland waterways as far as I could ascertain. However I found evidence of one that existed in the early 20th Century at the Foxton Locks. These were found in Leicestershire along the Grand Union Canal. The satellite image shows the ruins of the old inclined plane with functional locks on the left.
It’s an odd concept about halfway between a lift and a lock, with characteristics of both. Like a lock, it conforms to the contours of the landscape. Like a lift, it uses counterbalances to create a single continuous motion. Wikipedia has a nice photograph of an inclined plane in action on the Marne-Rhine Canal in northeastern France. It looks really strange.
The inclined plane at Foxton Locks reduced travel time from 75 minutes to 12 minutes but there wasn’t sufficient barge traffic to make it viable economically. Restoration, however, is underway with the increased interest in recreational canal boating. Britain may have an inclined plane once again.
Are any of the readers of the Twelve Mile Circle familiar with these or similar structures? Please share your findings in the comments.