The Bellovaci were among the most powerful and numerous of the Belgic tribes of north-eastern Gaul conquered by Julius Caesar in 57 BC. The name survives today in the French city of Beauvais, called by the Romans Caesaromagus.
The territory of the Bellovaci extended from modern Beauvais to the Oise River, along the coast. Beauvais is a French city approximately 77.6 kilometers north of Paris. The Bellovaci neighboured six tribes, Ambiani, Viromandui, Suessiones, Veliocasses, Caleti and Parisii.
The Bellovaci meant, possibly, the "shouters", the root word bel- is found in the Irish word beal, which means mouth and also Bel Bial means WHITE in other Indo-European languages. The Latin word bellum means war, and the root vac- means empty. However, there is no known record of a naming of the Bellovaci. The bell- root is also present in the name of Bellona, an Ancient Roman goddess of war.
Caesar's Campaign in Gaul 
This campaign occurred in the Compiègne Forest, in an area that had been occupied by the Suessiones. The Bellovaci intended to conquer this territory, a situation that Julius Caesar feared would expand into a greater threat and he decided it would be useful to correct the conflict to prove Roman superiority.
Caesar ordered troops into the territory of the Suessiones but chose to confront the Bellovaci himself. The Bellovaci, led by Correus, camped at Mount St. Marc, intending to attack head on if Caesar brought three legions, and to use guerrilla tactics if he brought more. The Roman camp was located at Mount St. Pierre, and heavily fortified with two ditches and two lines of defendants. The events of this campaign were recorded by Aulus Hirtius, though his findings do not entirely correspond with the geography of the region – he provided only that the Bellovaci camped at a “high wooded place surrounded by marsh”.
The Bellovaci were surprised by the arrival of Roman troops, and Julius Caesar was intimidated by the size of enemy forces, even though he (Caesar) had a large force of about 30,000 men with him, including 4 legions, tribes, and a few baggage trains. Neither initiated battle.
The battles were initially small confrontations with varying success across the marsh surrounding Bellovaci territory. The Belgic warriors set traps in the woods for Roman foragers, and maintained an immensely advantageous position to the point that Caesar was forced to call for reinforcements of three legions from Trebonius. Intimidated by the pending arrival of Roman reinforcements and fearing a siege, Correus sent many of his battle-incapable troops to escape in the night They accomplished this successfully, though Caesar's troops may have been able to catch them had they attempted to intervene.
Defeat and post-conquest period 
Eventually Caesar built a bridge crossed the marsh by Mount St. Marc, positioning his troops within missile range of the Bellovaci camp. Correus and the Bellovaci retreated in the night to a stronger camp 10 miles away, using a line of fire to blind the Roman troops, leaving traps in their wake to impede Roman pursuit. Correus then attempted an ambush on Caesar's troops, though not their entire number, sending about 6000 of his men to a spot where he believed Caesar would forage for food. Caesar heard of this, although it is not clear how, and has reinforcements ready to attack once the ambush is set off; however by the time he arrives, the Bellovaci were defeated, and their general Correus killed. After the battle, the Bellovaci were allegedly impressed by Caesar's clemency, which was secured through unclear means by Diviciacus.
- Strabo (July 1918). In Bill Thayer. The Geography of Strabo, Book IV. Loeb Classical Library.
- Ross, Josephine H (May 1939). "In Behalf of Caesar's Enemies". The Classical Journal. 34, 8: 449–460.
- Forbes, Henry O (March 1922). "The Topography of Caesar's Last Campaign against the Bellovaci". The Geographical Journal (The Geographical Journal, Vol. 59, No. 3). 59, 3 (3): 195–206. doi:10.2307/1781759. JSTOR 1781759.
- Holmes, T. Rice (January 1931). "The Topography of Caesar's Campaign against the Bellovaci (51 BC)". The Geographical Journal. 61, 1: 44–48.
- Peck, Harry Thurston (1898). "Bellovaci". Harper's Dictionary of Classical Antiquities. Harper Brothers.
- Coulter, Cornelia Catlin (April 1931). "Caesar's Clemency". The Classical Journal. 26, 7: 513–524.
- Radin, Max (July 1918). "The Date of Composition of Caesar's Gallic War". Classical Philology. 13, 3 (3): 283–300. doi:10.1086/360180.