The Nervii were one of the most powerful Belgic tribes living east of the Scheldt in north-eastern Gaul in the 1st century BC. The exact date of their inception and destruction is not known. They were considered the most warlike of the Belgic tribes.

Their culture was a spartan one; they purportedly would not partake of alcoholic beverages or any other such luxury, feeling that the mind must remain clear to be brave. Records indicate that they had no trade or merchant class of any kind, which would lead to the assumption that they had no currency, and were probably not very rich or advanced people.

The Nervii were part of the Belgic alliance that resisted Julius Caesar in 57 BC. After the alliance broke up and some tribes surrendered, the Nervii, under the command of Boduognatus and aided by the Atrebates and Viromandui , came very close to defeating Caesar (the Atuatuci had also agreed to join them but had not yet arrived). They concealed themselves in the forests and attacked the approaching Roman column at the river Selle (Northern France). Their attack was so quick and unexpected that some of the Romans didn't have time to take the covers off their shields or even put on their helmets. The element of surprise briefly left the Romans exposed. However Caesar grabbed a shield, made his way to the front line, and quickly organised his forces. The two legions who had been guarding the baggage train at the rear arrived and helped to turn the tide of the battle. Caesar says the Nervii were almost anihilated in the battle, and is is effusive in his tribute to their bravery, calling them "heroes".

When Ambiorix and the Eburones rebelled in 53 BC, the remaining Nervians joined the uprising and besieged Quintus Tullius Cicero - brother of the orator - and his legion in their winter camp untill they were relieved by Caesar in person.

The Nervii’s capital city seems to have been at Bagacum , also known as Bavay .

All figures in this article were taken from "Gallic Wars" by Julius Caesar. Some aspects of this may be tilted to make Caesar look better, but the basic elements can be taken as fact.