He reoccupied many forts built by Agricola over 100 years earlier, following the Battle of Mons Graupius, and crippled the ability of the Caledonians to raid Roman Britain.

The cause of Severus' invasion of Caledonia (modern day Scotland) was a massive increase in raids and attacks on Roman Britain.

This was possible because in 195 Clodius Albinus, the Roman Governor of Britain, had led most of the British legions into Gaul during his revolt against Severus.

This led to many of the tribes attempting to reach a peace agreement with Severus because of fear of extinction through Roman genocide.

[5] In early 210 Severus' son Caracalla led a punitive expedition north of the Antonine wall with the intention of killing everyone he came across and looting and burning everything of value.

Although forts erected by the Roman army of the Severan campaign were placed near those established by Agricola and were clustered at the mouths of the glens in the Highlands, the Caledonians were again in revolt in 210–211 and these were overrun.

[6] The Romans never campaigned deep into Caledonia again because they lacked spare forces to continue dealing with attacks as most manpower was redirected to secure other occupied lands.

The enemy purposely put sheep and cattle in front of the soldiers for them to seize, in order that they might be lured on still further until they were worn out; for in fact the water caused great suffering to the Romans, and when they became scattered, they would be attacked.