Sometime in the summer of AD 43 the Roman general Aulus Plautius embarked from Gaul to Britain, with an army of some 40,000 legionaries and auxiliaries. The progress of this invasion and conquest is not part of Scottish history, until the late 70s AD, by which time Roman troops had reached Carlisle and Newcastle and were ready to advance across the Cheviot Hills.

In 78 a new governor was sent to Britain. He was Julius Agricola, who had been born a Gaul (and therefore must have had Celtic blood) and who had already served in Britain, as a young officer. He knew the British: he may have come across Celts from southern Scotland or even some Caledonians from the north. By 78 his province consisted of virtually all England and Wales. Agricola was soon to become the first Roman general to advance into Scotland and to fight the Celts in a major battle, though not the first to send Roman troops across the Cheviot Hills. That had been done by his predecessor, Sextus Julius Frontinus.

The Celts in Scotland will not have remained idle while Roman armies were working their way up Britain towards them. There was no central government or dominant chief in Scotland to co- ordinate the national defences. Celts did not work like that; they never did, to their cost time and again in their history. But individual tribes and communities made some preparations. A hill- fort or two may have been additionally fortified. Crannogs in Galloway were strengthened. New duns were built and older ones repaired. Some brochs in the southern areas were put in readiness. One hill-fort thought to have been strengthened at this time is The Chesters, near Drem in East Lothian. It received extra ramparts.

In 80 Agricola launched a full-scale two-pronged invasion of Scotland. One army moved up the Annan river valley, known as Annandale, and the other through Lauderdale. Both paths were extremely difficult for a fully equipped army to march through. There were no proper roads as Agricola had had no time to build them, as his predecessors had done farther south, and the countryside was in turn hilly, marshy, thickly forested or filled with lakes. If the Celtic tribes could have combined their forces they would have been able to descend upon both columns, one after the other, and cut them both to pieces. They knew the terrain while the Romans did not. But the Celts did not get together, and the Romans succeeded in meeting as far north as Inveresk. Agricola then took the two columns together further into the land between the Forth and the Clyde. Detachments were filtered off southwestwards into Galloway, there to deal with Novantae warriors who would not yield to Roman persuasion to join them. The Roman forces in Galloway built forts of their own with which to overawe the Novantae and to police the district.

By 83 Agricola was ready for an attempt to break into the northern part of Scotland. He had sent a fleet from his harbour on the Solway up towards the Western Isles to explore the possibility of attacking the Caledonians from the west by seaborne invasion, and another fleet similarly went up the eastern side towards Aberdeen. But the idea seems to have been abandoned, for in 83 Agricola advanced on land from a line of forts he had established in the Forth-Clyde district, up into Tayside territory, and the edge of the Highlands. It is thought his route went through Strathallan, Strathearn and Strathmore. Some 30,000 troops marched towards Stirling, then on to the foothills of the Grampians in search of the main Caledonian forces. There was a minor skirmish with the Caledonians, probably near Inchtuthil, near Dunkeld, where a legionary fortress was built, though not finished, in the years 85–7, after Agricola’s departure from Britain. Under cover of darkness a Caledonian raiding party attacked the camp of the IXth Legion and killed the guards. Agricola came to the garrison’s relief with a force of infantry and cavalry, and drove the attackers off. But he realized that a major battle had still to come. Britons captured by Roman forward patrols revealed that the Caledonians were planning an all-out assault on the Roman forces. This may have been the first time that Agricola actually heard the name of the Caledonian leader, which was Calgacus. That is the Romanized form of the Celtic word calgaich, meaning swordsman.

The story of the Agricolan adventure into northern Scotland is well told by his son-in-law Tacitus. We may be sure that Tacitus’s military details were substantially correct but the time factor is difficult to grasp. The skirmish took place in 83, but the showdown was not until 84. Does this mean that though Agricola beat off the preliminary attack he did not think his position yet strong enough to take on the full brunt of the Caledonians? Was the skirmish a bigger affair than Tacitus suggests? It would be understandable for him to play down the reverse. What sort of forts and roads did Agricola establish at the time? The picture is not yet clear. Some authorities believe there were no Agricolan forts north of the Forth-Clyde isthmus. Both sides withdrew after the skirmish more than ever determined to bring the matter to a head. ‘We must drive deeper and deeper into Caledonia and fight battle after battle till we have reached the end of Britain’, was the feeling among the Roman troops. Meanwhile, every man among the Caledonians was urged to arm himself, put his wife and children into a place of safety and bury any differences he might have with any neighbour or rival. The Caledonians realized they must unite if they were to have any chance of success. Would they be able to do so?

By the summer of 84, Agricola was ready for the critical battle. To this day, the actual site of the battlefield is not known with absolute certainty. The northernmost military camps of the period have been found as far as Aberdeenshire and Banff-Moray. In 1970 it was persuasively argued by Richard Feacham that Duncrub, in the Earn Valley, between Perth and Auchterarder, was the site, but in 1978, J. K. St Joseph published results of fresh research by himself and David Wilson, both of the Cambridge University Aerial Photography Unit, taking the site much higher up the north east to the hill mass of Bennachie, 5 1/2 kilometres south-west of Durno (site of an Agricolan camp), which is not likely to be contested in the foreseeable future. It has the additional merit of helping to explain the year’s delay by Agricola in bringing on the clash. Tacitus calls the site Mons Graupius which has led to it being confused with the Grampian mountains. That summer day saw 30,000 Caledonians, fearless warriors, ‘tall, fair or red-haired… in primitive tartan, their shields and helmets

gay with enamel… followed by thousands of half-naked, barefoot infantry, bearing small, square, wooden shields, with a metal boss over the handgrip, and spears, with a knob at the butt end, which could be clashed with a terrifying noise,’ assembled on a hillside ready to meet some 8000 well-drilled auxiliary infantry backed by some 5000 auxiliary cavalry, and with short, cutting, stabbing swords, led by a commander who, in the heat of the battle, was to dismiss his horse and fight on foot at the head of his men.

The only account of the battle is that of Tacitus. Ten thousand Caledonians fell. The rest fled from the field back to the hills. Fewer than 400 Romans were slain. ‘On the succeeding day, a vast silence all around, desolate hills, the distant smoke of burning houses, and not a living soul descried by the scouts, displayed more amply the face of victory.’ Agricola ordered the commander of the Roman fleet, which had sailed along the eastern coast while the army was moving northwards inland and, presumably, was in harbour somewhere near the battlefield, to proceed north and ‘sail round the island’. Agricola, meanwhile, pulled back his cavalry and infantry, marching slowly to impress more deeply the might and majesty of Roman arms upon the conquered peoples, south to winter quarters, probably in the Forth-Clyde area, to forts established during his earlier campaigns. Soon afterwards, Agricola himself was recalled to Rome and a new governor was sent out in his place, who may have been Sallustius Lucullus.

Tacitus described Mons Graupius as a great Roman victory: who can blame him? But was it? The fact remains that Agricola retired southwards when it was over. Moreover, when he left Britain a few months later, the frontier between the Romans and the Caledonians was nowhere near Moray. It was more than 150 miles south, and over the years that followed, the Roman occupation of Scotland contracted and contracted. It probably never consisted of more than the holding of key forts and fortlets, and as time went by less and less of them. By 117, the year of the succession of Hadrian as emperor, there was fresh trouble in northern Britain. Some kind of revolt had broken out, possibly among the Selgovae and Novantae tribes (who were not Caledonians) in Galloway, and it is thought they may have linked up with discontented elements among the Yorkshire/Lancashire Brigantes.

Hadrian visited Britain in 122, and this is the year generally given as the one in which he ordered the construction of his famous wall. It eventually became 73 miles long and 12 to 15 feet high, with mile-fortlets and towers, from the Tyne to the Solway Firth. It was built to keep separate peoples like the Selgovae and Novantae from the Brigantes who were prone to creating trouble. It was also intended as part of Hadrian’s policy of consolidating the frontiers of the Roman empire. When he arrived in Britain there was not much that was Roman north of the Cheviot Hills.

In one respect this puts the ‘victory’ at Mons Graupius in a different light, certainly from the Caledonian point of view. But if Calgacus, or a succeeding leader, learned not to confront the Romans in open battle, that does not make Mons Graupius a decisive victory for Rome. At best it must have been only a tactical success, and the Caledonians could rightly feel they had discouraged the Romans from pushing any deeper into their territory. If Tacitus’s figures are right, 10,000 Caledonians slain left 20,000 still living, from a total force of 30,000. Perhaps half of these were unhurt, fit and ready if need be to fight again. Calgacus himself may have survived. If he did, he would have learned, as Boudica had learned twenty-four years before, that confrontation in the field of battle was not the way to beat the Romans. Harassment of Roman camps, marching columns and so on by small, swift raiding parties of well-armed guerrillas was much more effective, and this is what followed, whether organized by Calgacus or by a replacement chief.

The building of Hadrian’s Wall was by the standards of the Roman world an impressive achievement, but it did not keep the Caledonians, or any other enemies, out of Roman Britain. The actual work took about eight years, and this included building a milecastle every 1620 or so yards, as well as several forts for garrisons of infantry and cavalry and the buildings they needed. To begin with, part of the wall was made of stone and part of turf and timber (where stone was in short supply), though all turrets were of stone. There was a ditch on the northern side, 8–12 m. wide and 3–4 m. deep, separated from the wall by a space 20–40 feet across. Below the south wall was another ditch, with ramparts on either side. This was the Vallum. Between the ditch and the wall was a road. While each milecastle had accommodation for twenty-five to thirty men, and each turret for a handful, and several larger forts like Housesteads and Chesters accommodated several hundred men each, it still proved impossible to stop raids from the north altogether. The Caledonians moved about in small, well-trained teams of 100 to 200 tough warriors, and unless they came up against the full force of 1000 men, both cavalry and infantry, from a fort, they were often too much for the smaller roman garrisons. We do not know how often or where the Caledonians broke through, but in the 140s things had got so bad that Hadrian’s successor as emperor, Antoninus Pius, sent fresh forces to Britain. He ordered Scotland to be invaded again. In about 142 the governor of Britain, Lollius Urbicus, marched into southern Scotland and compelled the Novantae, the Selgovae and the Votadini to submit. Then he advanced to the line between the Forth and the Clyde where a few earlier forts and fortlets stood, desolate, unused, damaged, but strategically valuable. He rebuilt some and constructed new ones, making a chain of forts spaced out at regular short intervals along a turf and timber wall, on firm stone foundations. One fort you can see remains of today is Rough Castle, near Bonnybridge in Stirlingshire.

Each of the ends of the fort line was accessible from the firths and could be guarded by ships. It came to be known as the Antonine Wall and it was garrisoned for at least 20 years. It was breached several times. There were many ways in which the Caledonians could raid Roman-occupied territory. They could make a frontal assault on the wall. They could sail down either east or west coast and land somewhere ashore below the line of the wall. Or they could draw the Roman garrisons out of their forts, fight them in the field and defeat them, and then charge into Roman land simply by running through undefended gateways.

Both Hadrian’s and the Antonine Wall were psychological as well as physical barriers. They marked boundaries, as it were. But neither side for a moment imagined them to be impregnable. Perhaps the Romans did not even intend them to be.