The Battle of Mons Graupius took place in 84 A.D. when the Romans marched on the main granaries of the Caledonians. Up to this point the Caledonians had avoided open battle, preferring a guerilla raiding style but with their food under threat they had no choice but to stand and fight.
20,000 Romans under Governor Julius Agricola faced around 30,000 Caledonians under Calgacus and defeated them easily. The Caledonian forces were routed by Roman cavalry. Agricola´s biographer Tacitus claimed afterwards that 10,000 Caledonians fell for just 360 Romans but this seems rather unlikely.
After the battle many Caledonians escaped into the hills and Agricola withdrew. The actual site of the battle has never been confirmed. After this battle it was hastily proclaimed that Agricola had subdued all the tribes of Britain but events over the next few years were to prove him wrong as the northern tribes continued to cause havoc for the Romans.