In 1959 during excavation of the legionary fortress at Inchtuthil near Dunkeld headed by Sir Ian Richmond, archaeologists uncovered a singularly remarkable haul of a single kind of artefact.
Located in a twelve-foot deep pit below the beaten earth floor of the workshop – the Fabrica- was a remarkable hoard of nails, over eight hundred thousand in number, many in a remarkable state of preservation.
The find, concealed in antiquity beneath six feet of gravel back-fill was lucky by any standard in the days before archaeologists used metal detection or ground penetrating scans and was all the more remarkable as nothing to match the finds sheer quantity in one single deposit had – or has since – been found to rival it.
During the dig, a large “crust” of nails, was uncovered. As this had been subject to dampness in the ground the rusty mass was fused into a fairly unrecognisable mass. Once this was lifted out of the ground however the archaeologists were astounded to unearth the rest of the cache of nails extending below. The crust above had acted as a sacrificial layer absorbing ground and atmospheric moisture leaving the nails below in a remarkable state of preservation. Among the nails were other items of worked iron from the workshops. The haul though was predominantly of nails.
The nails range in size from small nails between thirty-eight and seventy millimetres long up to the massive spikes three hundred and seventy-two millimetres long (Figure 1). The smaller nails would have been used for general joinery work in timber frame buildings like barracks. Larger nails would have been used for clenching mortice joints in larger pieces of timber: rafters and the like.
The most massive nails, extremely rare to be preserved so well would have spiked together the primary timbers of the defensive tower’s frame. Simply driving such nails home would by no means have been a straightforward affair and it is probable the majority of the pilot hole in the timbers would have been drilled with some form of auger bit before the nail was pounded in the last few inches to act like a modern bolt pulling the pieces together.
All nails were handmade at the forge, and we can only marvel at the sheer manpower involved in making these nails. The nails are generally square in section, tapering gently from head to tip. The heads tend to have fairly amorphous shapes where they were beaten out on the anvil compared to the drawn and stamped manufactured products of today (Figure 2).
Finding the occasional nail at Roman sites is not unknown. However, the sheer quantity of the find at Inchtuthil illustrates how many of them were required in the construction of Roman forts. The reason so few are recovered from fort sites is that on abandonment the fort was usually burnt, this being the easiest way once the ashes cooled of allowing the recovery of the iron nails, iron being a valuable recyclable commodity.
So why were there so many nails at Inchtuthil and why were they buried?
Construction of the fortress at Inchtuthil, Ptolemy`s “Victoria”, most probably got underway the year or so after Agricola’s victory over the Caledonians in 83 AD at Mons Graupius. While Agricola might have had a hand in identifying the site for the fortress, it is more probable that it was during the tenure of his successor – Sallustius Lucullus – that the fort was planned.
Dating evidence of coins found at the site and at the other forts along the frontier network the Romans constructed facing the highland massif at this time suggests the outpost’s untimely abandonment as early as 87 AD, certainly no later than 90 AD. The reason behind this change in imperial policy in the highlands of Scotland was due to the withdrawal at this time of one of the four legions which formed the core of Britain’s garrison along with a matching contingent of auxiliary troops. This reorganisation appears to have been caused by a reappraisal of priorities with subsequent unit relocations following a series of sharp reversals of fortunes elsewhere in the empire.
A legionary fortress would have taken several years to complete, the task at Inchtuthil would have been made more difficult due to the logistical complications of supplying many of the construction materials required if they could not be found locally. One such item that could fall into this classification would be raw iron. The Romans normally relied on the pig iron ingots manufactured in foundries elsewhere in the empire and requiring transport from the Roman’s main supply depots some distance to the south.
The fortress appears to have been substantially complete at the time of its abandonment, with only elements such as the Commanding Officers house -The Praetorium- not having been built yet. That work is likely to have dragged on somewhat is suggested by archaeological findings that the defences, originally of timber were rebuilt in stone, a process that will not have assisted in the speedy completion of the works.
Inchtuthil did not sit alone. Its siting shows it was clearly intended to be the lynchpin in a network of forts ranging up from Doune to Stracathro in Angus, a network of posts which constituted Rome’s second frontier in Scotland, the first being Agricola’s chain of forts built across the Forth – Clyde isthmus some four years earlier.
Stracathro in itself does not readily spring to mind as a logical terminus for such a line of forts, it is therefore probable that more Roman forts – if not built – were certainly planned to occupy ground further north. These would have aimed for the strategically key position at the Mounth near Stonehaven, and as such would consolidate Rome’s hold over the lands of the tribes recently defeated at Mons Graupius.
Logically then, with Inchtuthil substantially complete, most of this vast store of nails must have been earmarked for these future works and were either stored at Inchtuthil or made in the workshops there – in itself a massive undertaking.
The find of the nails therefore gives us a salutary insight into a single snap-shot in time. The stockpile of nails would, upon receipt of instruction from the governor to abandon the frontier installations, have been a considerable item to transport south, weighing almost ten tons.
Some archaeologists’ reports give an unrealistic impression of the lengths the Romans would go to when dismantling a fort and exhibit a lack of appreciation of the apparent chaos on construction sites not to mention that on demolition sites. These archaeologists claim a piece-by-piece demolition with almost forensic care taken to pound waste into dust which was then used to pack mundane items such as drainage gullies, all to render the site unusable to the enemy as well, some claim, as a conservationist approach of ensuring the ground was returned to its virgin state. Unfortunately, this is complete nonsense.
Once the main defences were slighted, the Romans involved in decommissioning a fort – there may not have been a large body of them – were without defences and therefore vulnerable to locals who may wish to take retaliatory action against their former overlords who were now clearly in the business of quitting their lands. Old scores could and would be settled. Examples of temporary camps to house such bodies of troops during these suggested lengthy demolition works are recorded with certainty nowhere.
Evacuation therefore will more realistically have involved slighting of parapets and the gateways of the defences (“razing” the defences), removal of inscriptions and fine masonry which would be embarrassing if it fell into native hands and a general clear up of anything which could be off value to the natives -this usually being dumped and buried in pits or the forts well with the installations of the fort being put to the torch. The abandoned site will not have been “forensically” clean at all but will have been in a very sorry state indeed.
Of the many items that would have been of practical use to the tribes, iron was to the fore. The tribes of Scotland were intrinsically war-like and Roman historians record that they valued iron above gold or silver as it was the material with which weapons were made. Finding the cache of nails therefore would have constituted a God-send to the tribes and one that the Romans would have been understandably reluctant to pass on to them.
That the Romans did not transport this hoard south points in itself to a more hurried evacuation than the clinical approach mentioned above suggests.
Therefore we can envisage a hard-pressed Centurion, with what carts remained loaded and ready to go left wondering what on earth to do with this mass of nails. It does not take much to explain his decision logically. A squad of men will have been ordered to dig a hole in the ground of the workshop and dump the nails into this. We can reflect that this task in itself will have taken some time to do. On completion, the ground was obviously beaten flat and hard to remove any trace of what had taken place. Finally, the workshops themselves were set alight providing the deposits funerary pyre, the collapsed remains of the building further masking the buried hoard.
Archaeology shows that some timber posts from the workshop were dug out for re-use showing the flames did not consume all. That the natives will have dug out the timber is certain as the Romans clearly did not have the means to transport re-usable building products south, the nails being valuable manufactured products would have taken priority. Obviously the great care the soldiers took to conceal the pit was successful as the natives did not discover it.
The time it will have taken to do all this, coupled with the obvious fact that the abandoned nails and shoddy burning of the buildings represent a less than orderly retreat leads to the conclusion that this Centurion and the contubernium work squad may in fact have been among the last to leave the burning fortress.
What happened next?
The nails’ subsequent history is of some interest. Clearly the nails were never discovered by the Caledonians. Once excavated the nails appear to have become something of a burden to the excavating team due to the sheer bulk of the find.
Richmond gifted many nails to various museums around the world but his academic priorities lay elsewhere and the hoard was stored at the Dalzell steelworks in Motherwell, where it was eventually recycled. Somewhere, there are products of steel driving around, or on families dining tables with iron content from the Roman nails of Inchtuthil. As a recyclable commodity then, the material of the nails lives on.
Where did the iron come from?
Pig iron was commonly imported into Roman Britain from iron-producing areas of the empire- notably lower Germany- in small man-handlable billets. A fine example of one of these unworked billets is on show in the Trimontium Museum in Melrose which was discovered at Newstead.
As mentioned above, transporting heavy commodities such as iron will have been a major consideration to the Romans and they will have searched locally for sources of iron. The Roman name for the Dumnonii of Strathclyde – the “diggers” may reflect an early preponderance for the areas later reputed as the “workshop of an empire” and as a source of iron. The return in modern times of the nails to a foundry in Motherwell therefore is in certain respects fitting.
Another source of iron which has been overlooked to date however comes from closer to home to Inchtuthil. The fateful encounter of Mons Graupius almost certainly took place fairly close to Inchtuthil, not in the far north as no Agricolan camps survive there.
The abandoned weapons of the defeated tribes will have been a ready source of iron, the Romans will not have had any practical use for the haul of Caledonian weapons recovered from the field nor will they have wanted the weapons to remain in circulation among the native population.
It is therefore not altogether improbable that in some of the nails of Inchtuthil lives on the iron originally smelted for Caledonian weapons made to resist the Roman invaders in the north. If so it is ironic that this iron was reforged in Inchtuthils workshops as nails for the infrastructure of an ultimately doomed occupation. Remarkably, seldom has such simple humble iron survived to the present day, iron which played such an important part of and still pays silent testament to so much of Scotland’s early and most pivotal history.
Article first published on RomanScotland.org.uk in April 2008
