Cassius Dio’s Crazy (?) Maths

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The Taexali Game whisks 3 teens back in time to AD 210, to north- east Scotland during an era when the Ancient Roman Emperor Severus marched approximately 30 thousand soldiers in his legions all the way to the north east of Scotland.

I set the number to around 30,000 in my novel based on the estimated sizes of the marching camps at Kintore (44 ha/hectares) and Durno (58 ha). During the invasion of Agricola, and probably also during the era of Emperor Severus, those camps were very large—Durno being the largest Roman camp in Scotland that’s ever been found.

The ancient historian Cassius Dio’s version is that the Emperor Severus lost a ‘full fifty thousand’ troops during guerrilla warfare skirmishes with the northern barbarians (Maeatae and Caledonians) though no major battles occurred during those northern campaigns of Severus. Losing 50,000 soldiers en route north seems a tad unrealistic since that, to me, would entail Emperor Severus having had a lot more than that to start with on his northern Britannia campaign. 50,000 men would have been more than 8 legions lost to those guerrilla war faring Celtic tribes.

The total quota of legions across the Roman Empire during the Severan era, also according to Cassius Dio, was 33 legions, encompassing around 198,000-200,000 men. That would have meant that Emperor Severus would have had to have deployed around a quarter of the whole Roman Army to be in Britannia to engage in quelling the Caledonian barbarians.

From most sources we have to go on, the general amount of legions stationed in Britannia (post-AD 43) was 4—approximately 24,000 men. It seemed that deployment in Britannia demanded those 4 legions to quell the natives on the western fringes of the Empire. It appears to have been a constant need, but when there was trouble in Europe some of the troops were often redeployed elsewhere. That situation seemed to have happened during Agricolan times because General Agricola, and probably his successor, had barely begun to settle the natives of the north-eastern area (Scotland) when the troops were withdrawn, possibly to fight in Germania.

The Caledonian barbarians were a troublesome bunch, indeed. Emperor Septimius Severus came to northern Britannia to teach them a lesson they’d not forget in a hurry. Having been a constant thorn in the side of Rome those Maeatae and Caledonians were probably decimated when Severus did march to the Moray Firth. His policy was brutal …but more of that another day.

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