INCHTUTHIL ROMAN FORTRESS
Inchtuthil Legionary Fortress was intended as the lynch-pin of the Roman military occupation of northern Scotland. Home to the Twentieth Legion, it was positioned at the centre of a network of forts that encircled and contained the tribes of the Scottish Highlands. However, Roman military re-deployments meant that it was abandoned after only five years of use.
Inchtuthil, known to the Romans as Pinnata Castra, was probably established on the orders of General Gnaeus Julius Agricola around the time of Roman victory at the Battle of Mons Graupius in AD 83/4. Built and garrisoned by the Twentieth Legion (Legio XX Valeria Victrix), originally based in Wroxeter, it conformed to the traditional Roman design - a rectangular enclosure with rounded corners and gateways on each length. The curtain wall was initially an earth and timber rampart but its outer face was later revetted with a stone front. A single 'V' shaped ditch, approximately two metres deep and six metres wide, fronted the rampart. The site enclosed 53 acres - comparable to the Legionary fortresses at Caerleon and York which were the bases of the Second and Ninth Legions respectively. The location was also similar to the latter, it was positioned inland but on a navigable waterway (the River Tay) enabling easy resupply by vessels of the Classis Britannica (the British arm of the Roman Navy). General Agricola was well acquainted with York as he had overseen significant upgrades to the facility in the AD 80s and it is likely this had influenced his decision to establish the fortress at Inchtuthil.
Conquest and Control of Northern Scotland
Inchtuthil was part of a complex military deployment designed to contain the Highland massif. The Battle of Mons Graupius had seen Agricola defeat a large force - possibly 30,000 strong - raised from across a confederation of northern tribes which, according to a contemporary account by the historian Tacticus (Agicola's son-in-law), was headed by Calgacus. With such a significant defeat in open battle, the Romans anticipated that the Caledonian tribes would switch their tactics towards insurgency from the remote and isolated glens of Highlands. Inchtuthil - along with the associated network of forts, roads and watchtowers - was intended to contain this threat.
Agricola was an experienced military commander who had served in Britain during the Boudica rebellion and witnessed extensive operations to subdue and conquer tribes of Wales and Northern England. He was well aware fighting within the Highlands would require a costly and protracted campaign which favoured the Caledonians. Instead, he adopted a different strategy seeking to isolate and encircle the Highlands from the rich agricultural land in Aberdeenshire and Moray. This was achieved by:
1. Securing the Clyde-Forth isthmus. Agricola anchored his advance by building forts along the thin neck of land between the Rivers Clyde and Forth. Balmuildy, Cadder, Camelon, Castlecary, Mumrils and Old Kilpatrick forts were all founded at this time. Many of these installations were later re-occupied and incorporated into the Antonine Wall.
2. Glen Blocker system. The rough terrain of northern Scotland funnelled movement in and out of the Highland massif through a number of glens. A fort was constructed at each of these nodal points and garrisoned by an auxiliary regiment which ensured all movement could be supervised. Forts were established at Drumquhassle, Callander (Bochastle), Dalginross and Fendoch.
3. Gask Ridge Frontier. A frontier was established between the Rivers Forth and Tay. Its backbone was a Roman Road running from Camelon, north-west to Doune and then north-east towards Aberdeenshire. This included a chain of forts (including Doune and Ardoch) augmented by watchtowers and fortlets. A section of this frontier ran along a ridge of high ground running east-west which was the recipient of significant number of watchtowers - the so-called Gask Ridge. The frontier ended at Stracathro in Angus but had Roman occupation continued, construction of new facilities would probably have continued until the Romans had completely encircled all land access into the Highlands.
4. Twentieth Legion at Inchtuthil. Whilst the forts and fortlets along the frontier provided sufficient troops to deal with minor issues, the viability of the Roman occupation depended upon being able to surge a large and well equipped force to deal with major incursions. This requirement was met by the construction of Inchtuthil as a base for the Twentieth Legion, a unit consisting of over 5000 troops. The fortress was centrally located along the frontier enabling rapid reaction to any area as required.
Inchtuthil was centrally placed to enable rapid deployment to troublesome areas.
The Roman approach in Northern Scotland was probably similar to the operations previously conducted further south; first contain the threat by military encirclement and then establish control over food supplies. Had the Roman operation in Perthshire, Angus and Grampian continued the Roman conquest of Scotland would have become entrenched. However, events in central Europe took precedence and, judging by coin discoveries at the site, Inchtuthil was abandoned as a military base sometime during the period between AD 87 and AD 90. This conforms to known Roman military dispositions as, around AD 86/87, Rome permanently re-deployed one of the four Legions based in Britain; the Second Adiutrix Legion (Legio II Adiutrix Pia Fidelis) was sent to Dacia (modern day Moldova). The withdrawal of the integrated 5,000+ man Legionary force, along with a similar number of troops in the associated auxiliary regiments, forced the Governor of Britain, Sallustius Lucullus, to scale back the military operations in the province. With insurgency in the Pennines and Wales, the Twentieth Legion was relocated to Chester (Deva) leaving the Ninth as the northernmost force at York. This made Scotland untenable and accordingly the Romans commenced a staged withdrawal towards the Solway-Tyne isthmus. By AD 100 their Stanegate Road between Corbridge and Carlisle had become the new frontier - this would be entrenched as Hadrian's Wall in AD 122.
Inchtuthil had been occupied for around five years and seems to have been largely complete by the time it was abandoned; only the Praetorium (the Commanding Officer's House) and some of the accommodation for the Tribunes was incomplete. The speed of establishing the fortress is a testament to the efficiency, logistical prowess and industrial capability of the Roman military machine. In infrastructure terms the fortress was a town and for the Romans to establish it at this remote plain in the north of Scotland in just a matter of a few years is remarkable - production today would take much longer! The industrial achievement is perhaps best emphasised by the archaeological discovered in 1959 of a huge cache of Roman nails - in excess of 800,000 - ranging from small nails a few centimetres long to larger spikes used for the timber joints on the defensive arrangements. These were new, unused nails manufactured on the site presumably to support construction of the forts and watchtowers of the Glen Blocker and Gask Ridge systems. The weight of the nails was in excess of 10 tons almost certainly explaining why they were not taken south with the Legion. However, Iron was highly prized by the northern tribes - for its obvious weapon making properties - and so the nails were buried. As the Romans withdrew, they burnt Inchtuthil fortress to the ground and thereafter the site was abandoned.
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Inchtuthil Roman Fortress survives as slight earthworks with few visible traces of the vast installation that once occupied the entire field. Nevertheless, the site is undeveloped which enables the visitor to immediately appreciate the vast scale of the fortification. Had Inchtuthil remained in operation for longer, there would probably have been a city on the site now.
Inchtuthil Roman Fortress. The vast facility included 64 barrack blocks, a hospital, multiple storehouse and workshops. The Commanding Officer’s house and some small houses for the Tribunes were not completed before the fort was abandoned. Today only slight earthworks remain visible.
Fortress Site. The fortress occupied an area of approximately 53 acres.
Twentieth Legion. The fort was built by the Twentieth Legion and, had the occupation of Scotland continued, would have become their permanent base. However, after withdrawal from Inchtuthil the unit was stationed at Chester.
Take Care. The fort site is used by livestock. Take care when visiting.
Controlling Highlands. Inchtuthil, with its mobile force of 5,000+ infantry, was at the centre of a chain of forts and watch-towers designed to contain hostile forces.
River Tay. The fort site is partly wooded now and this obscures its proximity to the River Tay. This large waterway enabled the site to be resupplied by the Classis Britannica.
Inchtuthil Roman Fort forms part of a private estate and there are no signposts or parking facilities. A number of farm tracks lead to the site but CastlesFortsBattles.co.uk cannot comment on the legality of using them nor on use of the on-road parking option shown below.
Car Parking Option
Inchtuthil Roman Fort