"The whole race... is madly fond of war, high-spirited and quick to battle... and on whatever pretext you stir them up, you will have them ready to face danger, even if they have nothing on their side but their own strength and courage."
"Their arms correspond in size with their physique; a long sword fastened on the right side and a long shield, and spears of like dimension...”
“The Gaulish nobles wear clothes that have been dyed and shot through with gold”
“The Gauls wear clothes mostly of reds”
"The Insurbes and the Boil wore their trousers and light cloaks, but the Gaesatae had discarded their garments owing to their proud confidence in themselves... At first the battle was confined to the hill... In this action Galas the Consul fell in the melee fighting with desperate courage and his head was brought to the Celtic kings... All [the naked Gaesatae] in the leading companies [were] richly adorned with gold torcs and armlets. The sight of them indeed dismayed the Romans, but at the same time the prospect of winning such spoils made them twice as keen for the fight... [Later in the battle,] reduced to the utmost distress... some of [the Gaesatae] in their impotent rage, rushed wildly on the enemy and sacrificed their lives, while others, retreating step by step on the ranks of their comrades, threw them into disorder by their display of faint-heartedness."
"The Romans... were terrified by the fine order of the Celtic host, and the dreadful din, for there were innumerable horns -blowers and trumpeters, and the whole army were shouting their war-cries... Very terrifying too were the appearance and the gestures of the naked warriors in front, all in the prime of life and finely built men, and all in the leading companies richly adorned with gold torcs and armlets."
“The Gaulish warriors wear a striking kind of clothing, tunics dyed and stained in various colours as well as trousers, which they name Braccae”
"Their armour includes man-sized shields decorated in individual fashion. Some of them have projecting bronze animals of fine workmanship... On their heads they wear bronze helmets which possess large projecting figures lending the appearance of enormous stature to the wearer. In some cases horns form one part with the helmet, while in other cases it is relief figures of the foreparts of birds or quadrupeds. Their trumpets again are of a peculiar barbaric kind...and produce a harsh sound which suits the tumult of war. Some have iron breast-plates of chain- mail, while others fight naked...”
"And when someone accepts their challenge to battle they proudly recite the deeds of valour of their ancestors and proclaim their own valorous quality at the same time abusing and making little of their opponent and generally attempting to rob him beforehand of his fighting spirit."
"There is not much difference between [Britons and Gauls] in language, the same boldness in courting danger, and, when danger looms, the same panic in avoiding it."
Vindolanda Tablet no.164:
"... the Britons are unprotected by armour. There are very many cavalry.
The cavalry do not use swords nor do the wretched Britons dismount in order to throw javelins."
When it comes to our understanding of Iron age Warriors, both Hollywood & Victorian Misconceptions have a lot to answer for. Mention "Celts" to the average person and they will generally give you the same 3 collocations, "Naked Savages, Painted Blue, Head-Hunters". Even 30 years ago, the common stereotype was a people who sat in mud, wore mud, ate mud and were thankful for the Civilization that Rome brought to the Island.
In the Iron Age Warriors defence we can say that, had they been simply naked savages running headlong into battle and dying gloriously, then the "Ancient British Culture" would have ceased to exist within a few generations. We also know that warriors from client Kingdoms were welcomed into the Roman Legions, so clearly there was something about the "Celtic" Warrior which the Roman's valued. Their horsemanship, their large physical stature and their bravery for a few.
Let's try to glean some real evidence from the people who saw them, the ancient writers......