On 22 September 83 CE, the Battle of Mons Graupius was fought between the Romans under Gnaeus Julius Agricola and the Caledonians under Calgacus during the Roman Conquest of Britain.
Why did it happen?
In 77 CE, Gnaeus Julius Agricola returned to Britain as governor, having fought Boudica’s army at the Battle of Watling Street seventeen years earlier. Taking command of the four legions stationed in Britain, he immediately went on the offensive against the Celtic tribes in Wales and built forts at Carnarvon, intending to “civilise” the Britons. In 79 CE, Agricola sent two large columns of soldiers up into southwest Scotland, where he overawed the Brigantes and built forts as he went. He intended to conquer Ireland with only one legion, but in 83 CE, he was drawn to Scotland, where the Caledonian tribes had formed a confederation under Calgacus. With the permission of the Roman emperor Domitian, Agricola moved north along the east coast of Scotland supported by a fleet, where he met the Caledonian army at Bennachie Hill in Aberdeenshire in late September.
Who was involved?
The Roman army at Mons Graupius numbered 17,000 infantry and 3,000 cavalry. The Roman infantry consisted of 9,000 legionaries from the IX and XX Legions and 8,000 auxiliaries consisting of cohorts from Batavia and Tungria in Germany. The auxiliaries were placed in the vanguard under Aulus Atticus, and the legionaries in reserve under Agricola himself. The cavalry was placed upon the wings and would handle the Caledonian cavalry before attacking the flanks of the Caledonian infantry. According to Tacitus, Agricola planned for the auxiliaries to do most of the fighting because “victory would be vastly more glorious if won without the loss of Roman blood, and he [Agricola] would have a reserve in case of repulse” (Tac. Ag. 35). The Caledonian army consisted of 30,000 infantry, cavalry, and chariots. The Caledonian infantry was arrayed in two lines, with the first line on Bennachie Hill and the second line on the plain in front of it, with chariots in front of the infantry and cavalry arrayed on the flanks.
What happened?
As the Caledonian chariots drove back and forth across the plain, showering missiles on the Roman army, Agricola ordered 2,500 auxiliaries to engage the Caledonian chariots and infantry. At the same time, the Caledonian cavalry was routed and fled the battlefield, pursued by the Roman cavalry. As the rest of the Roman auxiliaries advanced to engage the Caledonian army, the Caledonian chariots intermingled with the infantry, which obstructed both sides. Nevertheless, the Roman auxiliaries continued to cut down the Caledonian ranks and advance uphill. The Caledonian infantry stationed on Bennachie Hill attempted to outflank and envelop the Roman auxiliaries by descending onto the plain. At that point, Agricola sent 400 cavalry to intercept the manoeuvre and attack the Caledonians in the flank and rear, causing the Caledonian army to flee. Roman casualties numbered 360 killed, while the Caledonians lost 10,000 killed.
What changed as a result?
The Battle of Mons Graupius was a Roman victory. In the aftermath of the battle, Agricola ordered a legionary camp for the XX legion to be constructed at Inchtuthil and sent his fleet north to circumnavigate Britain and confirm it was an island. However, just when it seemed that all of Britain was conquered, Domitian recalled Agricola in 84 CE to put down a rebellion on the Danube. The legionary camp at Inchtuthil was abandoned in 86 CE, and Rome’s advance into Scotland was abandoned until Hadrian set the northern frontier at Hadrian’s Wall in 122 CE. As stated by Nigel Rodgers, “From unconquered Scotland would later come many of the tribes that would threaten Roman Britain” (Rodgers, 2007, p.195). Beginning in 180 CE, Caledonian tribesmen conducted border raids into Roman Britain as far south as York, despite Septimius Severus conducting two campaigns against them between 209 and 211 CE. Rome would rule Britain south of Hadrian’s Wall until 410 CE when it abandoned the province to the Caledonians, Saxons and Irish.
Bibliography
Campbell, Duncan B. Mons Graupius AD 83: Rome’s battle at the edge of the world. Oxford, Osprey Publishing, 2010.
Grant, R.G. Battle: A Visual Journey Through 5,000 Years of Combat. London, Dorling Kindersley, 2005.
Rodgers, Nigel. The History and Conquests of Ancient Rome. London, Hermes House, 2007.
Tacitus. The Life of Gnaeus Julius Agricola. Translated by Alfred John Church & William Jackson Brodribb. New York, Random House Inc, 1942.