From 79AD onwards Agricola, Governor of Britain, drove northwards from York,in the east, and Chester, in the west. By 83AD he had reached the Highlands. In 84AD the Caledonian tribes under Calgacus assembled at Mons Graupius and awaited the Romans. Numbers were about equal. Agricola only used his auxillaries where superior tactics and training carried the day. Tacitus claimed 10,000 tribesmen were killed for the loss of 360 auxillaries.

Agricola was disappointed because about seventy per cent of the tribesmen escaped. Not only did they escape but they dispersed and were very difficult to hunt down. The Caledonians were left with sufficient strength to continue to threaten the northern border of the Empire. The eventual outcome was an acceptance by the Romans of the limit of their empire and the building of Hadrian's Wall the main structure of which was built from 122 AD to 126 AD.