Celtic Warfare - Gallic Wars

The Gallic Wars were a series of military campaigns waged by the Roman proconsul Julius Caesar against several Gallic tribes, lasting from 58 BC to 51 BC. The Romans would also raid Britannia and Germania, but these expeditions never developed into full-scale invasions. The Gallic Wars culminated in the decisive Battle of Alesia in 52 BC, in which a complete Roman victory resulted in the expansion of the Roman Republic over the whole of Gaul. The wars paved the way for Caesar to become the sole ruler of the Roman Republic.

The best known Roman source for descriptions of Celtic warfare is Julius Caesar in his Commentaries on the Gallic Wars (Commentarii de Bello Gallico) in which he describes the methods of warfare of both the Gauls and the Britons.

In describing battles against various tribes of Gauls, in contrast to the popular picture of the wild Celtic berserker, Caesar talks of the Helvetii fighting in close order, forming a phalanx as a defence against cavalry and advancing in a close formation. He also speaks of arrows being used against his troops crossing rivers and against the besiegers of Gergovia, capital of the Arverni - one of the few engagements in which Vercingetorix outmanoeuvred Caesar. He mentions the use of javelins by the Belgic Nervii, but despite Roman writers frequently referring to the use of swords by the Celts in battle, Caesar never mentions Gaulish troops fighting en masse with swords. By the mid-1st century BCE, Celtic tribes in Gaul may have had a core of properly trained and equipped professional soldiers, drawn from the traditional warrior caste, in addition and in contrast to the general tribal levy of lightly armed and armoured freemen.

It is perhaps the descriptions of the Britons which have most influenced the popular image of the wild Celtic warrior. Caesar emphasises the "barbarian" aspect of the Britons, possibly for political reasons since his expedition there was of necessity brief, describing how they wore animal skins, had wives in common, did not grow crops and dyed their skin blue: although this description does not mention the plant, subsequent commentators have supposed that woad was the source of this blue dye and though later experimentation suggests that woad is not very well suited as a skin dye nor as tattoo ink, this image, conflated with the descriptions of the Gaesatae, has nevertheless helped paint the picture of the woad-daubed ancient Briton charging into battle naked and blue.

Outside Britain, small pots of orange paste have been found in the vicinity of Cerro del Castillo, which has led to the proposition that if the Celtiberians used it in a similar manner to Caesar's description, they would have painted themselves orange rather than blue.

The other popular image of pre-Roman Britain, the scythed chariot, is not mentioned by Caesar either but alluded to by later commentators, such as Pomponius Mela, during and after the Roman conquest.