The Battle of Mons Graupius was, according to Tacitus, a Roman military victory in what is now Scotland, taking place in AD 83 or, less probably, 84. The exact location of the battle is a matter of debate. Historians have long questioned some details of Tacitus's account of the fight, suggesting that he exaggerated Roman success.
Context
According to Tacitus, Gnaeus Julius Agricola, who was the Roman governor and Tacitus's father-in-law, had sent his fleet ahead to panic the Caledonians, and, with light infantry reinforced with British auxiliaries, reached the site, which he found occupied by the enemy. Even though the Romans were outnumbered in their campaign against the tribes of Britain, they often had difficulties in getting their foes to face them in open battle. The Caledonii were the last unconquered British tribe. After many years of avoiding the fight, the Caledonians were forced to join battle when the Romans marched on the main granaries of the Caledonians, just as they had been filled from the harvest. The Caledonians had no choice but to fight, or starve over the next winter.
Battle details
According to Tacitus, 8,000 allied auxiliaryinfantry formed the center, while 3,000 cavalry were on the flanks, with the Roman legionaries as a reserve in front of their camp. Estimates for the size of the Roman army range from 17,000 to 30,000; although Tacitus says that 11,000 auxiliaries were engaged, along with a further four squadrons of cavalry, the number of legionaries in reserve is uncertain. The Caledonian army, which Tacitus claims was led by Calgacus, was said to be over 30,000 strong. It was stationed mostly on higher ground; its front ranks were on the level ground, but the other ranks rose in tiers, up the slope of the hill in a horseshoe formation. The Caledonian chariotry charged about on the level plain between the two armies. After a brief exchange of missiles, Agricola ordered auxiliaries to launch a frontal attack on the enemy. These were based around four cohorts of Batavians and two cohorts of Tungrian swordsmen. The Caledonians were cut down and trampled on the lower slopes of the hill. Those at the top attempted an outflanking movement, but were themselves outflanked by Roman cavalry. The Caledonians were then comprehensively routed and fled for the shelter of nearby woodland, but were relentlessly pursued by well-organised Roman units. It is said that the Roman Legions took no part in the battle, being held in reserve throughout. According to Tacitus, 10,000 Caledonian lives were lost at a cost of only 360 auxiliary troops. 20,000 Caledonians retreated into the woods, where they fared considerably better against pursuing forces. Roman scouts were unable to locate the remaining Caledonian forces the next morning.
Criticisms of Tacitus's account
The decisive victory reported by Tacitus was criticized by some historians, however, who believe an engagement of some description did not occur. One author has suggested that the emperor Domitian may have been informed of the fraudulence of his claims to have won a significant victory. Despite these claims, Agricola was awarded triumphal honours and was offered another governorship in a different part of the empire, so it would seem unlikely Domitian doubted he had achieved substantial successes. Suggestions that he invented the entire episode and was thereafter shunned by the emperor do not seem likely, given that he was awarded honours on his return.
Aftermath
Following this final battle, it was proclaimed that Agricola had finally subdued all the tribes of Britain. Soon after Agricola was recalled to Rome, and his post passed to Sallustius Lucullus. It is likely that Rome intended to continue the conflict but that military requirements elsewhere in the empire necessitated a troop withdrawal and the opportunity was lost. Tacitus' statement on his account of the Roman history between 68 AD and 98 AD: Perdomita Britannia et statim missa, denotes his bitter disapproval of Domitian's failure to unify the whole island under Roman rule after Agricola's successful campaign.