Celtic Warfare

The Celts were a linguistic group which spanned across a wide geographic area and included numerous cultures and ethnicities. The importance of warfare and the traditions surrounding war were one common thread of similarities throughout Celtic societies and cultures, from the earliest emergence of the Hallstatt culture (12th-6th century BCE) to the La Tene culture (5th-1st Century BCE). They had no regular military as we would understand it and organisation was according to clan grouping and social class.

Warfare was interwoven into Celtic social structures, art, religion, and lifestyle, and the Celts acquired a warrior reputation among their neighbours in the ancient world. While Celtic societies tended to be less well-organized than their Mediterranean counterparts, Celtic craftsmen worked iron, bronze, and gold with tremendous skill, and many technological innovations related to metalworking originated with the Celts.

Celtic Arms & Armor

The main sources of evidence about ancient Celtic arms and armour come from archaeological finds, Greek and Roman literary accounts, and art depicting Celtic warriors. The main Celtic weapons would have been a sword, usually fastened on the right side and a spear. The normal means of protection was the shield, but sometimes helmets were worn and less often tunics of ring mail. Read more about the Arms and Armour of the Celts.

Warfare & Celtic Society

Celtic tribes fought amongst each other and sometimes they allied themselves with the Romans, the Greeks and other peoples against other Celtic tribes. Tribal warfare appears to have been a regular feature of Celtic societies. While epic literature depicts this as more of a sport focused on raids and hunting rather than organised territorial conquest, the historical record is more of tribes using warfare to exert political control and harass rivals, for economic advantage, and in some instances to conquer territory.

Changes to Celtic Weapons and Warfare over time

Archaeology provides much information regarding the material culture of the Celts, but the significance of these finds in determining how the ancient Celts actually fought is the subject of much speculation. It was long thought, for instance, that the Celts were head-hunters, but recent research from France has indicated that it may have been the heads of slain allies that were collected to be placed in porticos, while the defeated were dumped in mass graves, their weapons ritually broken.

Celtic Warfare in the Hallstatt period 12th–6th centuries BC

The Hallstatt Culture is the earliest to be identified as associated with Celtic culture, spreading from north of the Alps west into France, Southern Britain and the Iberian Peninsula. The earlier phases of the Hallstatt era fall into the Bronze Age. Swords seem to have been the primary weapon from this period, perhaps indicating that warfare was a relatively small scale affair, possibly between groups of elite warriors. In the latter phases of the Hallstatt era, iron began to replace bronze in the manufacture of weapons, and the classic “Celtic longsword” with its leaf-bladed design made its appearance. Chariot burials are also characteristic of the period; it is possible that they also served a function in the warfare of this age, but the chariots are four-wheeled vehicles and they do not occur at all in Britain until the La Tène period. At the very end of the Hallstatt era, the longsword seemed to fall out of favour, ousted by short, thrusting daggers which are found in greater numbers among grave goods in high status burials.

Celtic Warfare in the La Tène period 6th–1st centuries BC

By 400 BC there are the Spanish Celts (Celtiberians), Gallic Celts, and from the Halstatt Celtic areas, La Tene Celts pushing down into Italy from the Alps. The Gauls actually move into the Balkans and become the Galatians about 250 BC. Others, the Belgic Gauls, push into Britain and fought/mixed with the native Picts.

The La Tène Period saw changing patterns of warfare. At the beginning of the La Tène period warfare was likely conducted on a small scale between elite warriors, perhaps in chariots, wielding a new type of Celtic longsword. During the succeeding centuries the design of the sword changed, characteristically becoming shorter, single-edged and lacking a thrusting point, designed purely to make a cut (although the Hallstatt era sword had also been primarily a slashing weapon).

Celtic Warfare in Different Regions

The different Celtic regions of formed it own culture to some extent, mixing with the indigenous peoples, and depending on period, different mixes of religions and military traditions. Greater regional variation in swords appeared: in Britain and Ireland even the longer sword designs were shorter and thinner than their Continental counterparts. It is possible that in the later La Tène era, an increasing population would have led to larger armies organised in ranks of spearmen, leading to a decline in the importance of the champion with his sword and hence a decline in sword functionality. The Celts in Spain took up the Spanish weapons and use of light infantry, which the Northern, Germanic tribes did not.

Fighting Styles and Tactics of the Celts

The classic Celtic image is provided in Strabo’s oft-quoted description:

The whole race . . . is madly fond of war, high-spirited and quick to battle, but otherwise straightforward and not of evil character. And so when they are stirred up they assemble in their bands for battle, quite openly and without forethought, so that they are easily handled by those who desire to outwit them.

Strabo, Geography, Book 4 Chapter 4

Celtic Single Combat

Single combat is again a clear sign of how the ancient Celts viewed warfare. It was always, above all else, a contest of honour among men, not a slaughter for territory or riches. Like the Greeks at Troy, Gaulish
fighters were only too happy to strip their slain enemies of rich spoils — but eternal glory, being celebrated by the bards in song for generations to come, was the ultimate goal of any Celtic warrior.

It is also their custom, when they are formed for battle, to step out in front of the line and to challenge the most valiant men from among their opponents to single combat, brandishing their weapons in front of them to terrify their adversaries. 3 And when any man accepts the challenge to battle, they then break forth into a song in praise of the valiant deeds of their ancestors and in boast of their own high achievements, reviling all the while and belittling their opponent, and trying, in a word, by such talk to strip him of his bold spirit before the combat.

Diodorus Siculus, The Library of History Book 5, Chapter 29

Celts Fighting Naked

One of the features of Celtic Warfare which is often stated in classical references is that some warriors fought naked, except the sword belt and a gold neck torc.

The Dying Gaul antmoose (CC BY-NC-SA 2.0)

The Dying Gaul or The Dying Galatian, is an ancient Roman marble semi-recumbent statue now in the Capitoline Museums in Rome. It is a copy of a now lost sculpture from the Hellenistic period (323-31 BC) thought to have been made in bronze. The original may have been commissioned at some time between 230 and 220 BC by Attalus I of Pergamon to celebrate his victory over the Galatians, the Celtic or Gaulish people of parts of Anatolia.

This order of the Celtic forces, facing both ways, not only presented a formidable appearance, but was well adapted to the exigencies of the situation. The Insubres and Boii wore their trousers and light cloaks, but the Gaesatae had discarded these garments owing to their proud confidence in themselves, and stood naked, with nothing but their arms, in front of the whole army, thinking that thus they would be more efficient, as some of the ground was overgrown with brambles​ which would catch in their clothes and impede the use of their weapons. […] 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 torques and armlets.

Polybius, The Histories of Polybius, Book 2, Chapter 29

When in 361BC the Roman Manlius confronted a Celtic chieftain in single combat, the Celt fought naked but for his shield, two swords and his torc and armlets.

Titus Livius (Livy), The History of Rome, Book 7? y (7.9.6)

Livy states the Galatians fought naked against the Romans during the Galatian War 189BC

Some of them have iron cuirasses, chain-wrought, but others are satisfied with the armour which Nature has given them and go into battle naked.

Diodorus Siculus, Library of History, Book 5, Chapter 30

At the battle of Cannae (216 BC) Polybius describes the naked Celts and the Iberians with their short linen tunics with purple borders, and Livy speaks of the Gauls naked from the navel up and of the Iberians with dazzlingly white tunics bordered with purple. 

Fighting naked was an act of audacity designed to show contempt for their opponents. To go naked into battle was a psychological tool intended to throw the enemy off balance before the fighting even began. However, when naked Celts are noted by classical authors, they are described as a minority on the battlefield. To fight without armor must have been a particular act of bravado that didn’t appeal to most Gaulish warriors.

Celtic Noise Before Battle

In their attempts to throw the enemy into confusion and terror, the Celts made great use of noise.  Polybius mentions the Celtic tactic of noise making on the battlefield, at the Battle of Telemon, in order to frighten the enemy.

[T]he dreadful din, for there were innumerable horn-blowers and trumpeters, and, as the whole army were shouting their war-cries at the same time, there was such a tumult of sound that it seemed that not only the trumpets and the soldiers but all the country round had got a voice and caught up the cry. 

Polybius, The Histories of Polybius, Book 2, Chapter 29

[The Gaul’s] trumpets are of peculiar nature and such as barbarians use, for when they are blown upon they give forth a harsh sound, appropriate to the tumult of war. 

Diodorus Siculus, The Library of History, Book 5, Chapter 30 (Battle of Telamon)

The sound of a Celtic war horn was a powerful psychological weapon against the enemy. Archaeologists have recovered a number of these trumpets from many places in the Celtic world. Unlike modern bugles, ancient Celtic horns were shaped like an extended S that stood several feet straight above the player. This height allowed the piercing sound to project long distances. The top of the horn was curved to the front and usually shaped in the form of an animal’s head—boars and wolves were especially popular.

Celtic Head taking

In the wake of battle the Celts often beheaded enemy corpses and displayed their grisly trophies, for they believed the captured soul resided in the head. It was also important for a warrior to take home the head of an enemy, not least because he had to prove that he was brave and strong—and victorious.

The archaeological evidence for the head cult among the Celts is extensive. At the Celto-Ligurian sanctuary of Entremont in southern Gaul (Provence), fifteen male skulls were found, several of them still bearing the marks of the spikes with which they had been fixed for display. At Bredon Hill in Gloucestershire, England, a row of skulls uncovered near the entrance seem to have fallen from above the gate of the fort.

Polybius mentions the decapitation of Consul Gaius at the Battle of Telamon 225 BC.

In the midst of it the Consul Gaius fell, fighting with reckless bravery in the thick of the battle, and his head was brought to the king of the Celts. 

 Polybius, Histories Book 2 Chapter 28 (Battle of Telamon 225 BC)

The Senones or Senonii were an ancient Gallic tribe dwelling in the Seine basin. In 391 BCE, under the chieftain Brennus, they invaded Etruria and besieged Clusium. After a battle between the Senones and the Romans the consul got no news of the disaster that had overtaken one of the legions until they saw a victorious Gaul with heads hanging from his horse.

[T]he consuls, who were not far from Clusium, got no report of the disaster till some Gallic horsemen came in sight, with heads hanging at their horses’ breasts or fixed on their lances, and singing their customary song of triumph

Titus Livius (Livy), The History of Rome, Book 10

Livy tells us of the customs of the Celtic Boii of northern Italy.

Here Posthumius fell, fighting with all his might to prevent his being taken. The Boii, having cut off his head, carried it and the spoils they stript off his body, in triumph into the most sacred temple they had. Afterwards they cleansed the head according to their custom, and having covered the skull with chased gold, used it as a cup for libations in their solemn festivals, and a drinking cup for their high priests and other ministers of the temple. 

Titus Livius (Livy), The History of Rome, Book 23, Chapter 24

During the Punic War (218 BC), a Celtic contingent in the Roman army, believing that Hannibal’s prospects were brighter, killed some Romans and, cutting off their heads, departed with them to join the Carthaginian.

But the Celtic contingent of the Roman army, seeing that Hannibal’s prospects looked the brighter of the two, concerted their plans for a fixed time, and waited in their several tents for the moment of carrying them out. When the men within the rampart of the camp had taken their supper and were gone to bed, the Celts let more than half the night pass, and just about the time of the morning watch armed themselves and fell upon the Romans who were quartered nearest to them; killed a considerable number, and wounded not a few; and, finally, cutting off the heads of the slain, departed with them to join the Carthaginians

Polybius, Histories Book 3 Chapter 67

 Chiomara, the wife of Ortiagon, was captured with the other women when the Asiatic Gauls were defeated by the Romans under Manlius. The centurion into whose hands she fell took advantage of his capture with a soldier’s brutality and did violence to her. The man was indeed an ill-bred lout, the slave both of gain and of lust, but his love of gain prevailed; and as a considerable sum had been promised him for the woman’s ransom, he brought her to a certain place to deliver her up, a river running between him and the messengers. When the Gauls crossed and after handing him the money were taking possession of Chiomara, she signed to one of them to strike the man as he was taking an affectionate leave of her. The man obeyed and cut off his head, which she took up and wrapped in the folds of her dress, and then drove off. When she came into the presence of her husband and threw the head at his feet, he was astonished and said, “Ah! my wife, it is good to keep faith.” “Yes,” she replied, “but it is better still that only one man who has lain with me should remain alive.” Polybius tells us that he met and conversed with the lady at Sardis and admired her high spirit and intelligence.

Polybius, Histories 21.38

This head taking and the preservation of the heads of the most distinguished enemies was a practice which had for the Gauls a religious and a magical significance.

When their enemies fall they cut off their heads and fasten them about the necks of their horses; and turning over to their attendants the arms of their opponents, all covered with blood, they carry them off as booty, singing a paean over them and striking up a song of victory, and these first-fruits of battle they fasten by nails upon their  p175 houses, just as men do, in certain kinds of hunting, with the heads of wild beasts they have mastered. 5 The heads of their most distinguished enemies they embalm in cedar-oil and carefully preserve in a chest, and these they exhibit to strangers, gravely maintaining that in exchange for this head some one of their ancestors, or their father, or the man himself, refused the offer of a great sum of money. And some men among them, we are told, boast that they have not accepted an equal weight of gold for the head they show, displaying a barbarous sort of greatness of soul; for not to sell that which constitutes a witness and proof of one’s valour is a noble thing, but to continue to fight against one of our own race, after he is dead, is to descend to the level of beasts.

Diodorus Siculus, Library of History, Book 5, Chapter 29

‘When their enemies fall’, writes Diodorus Siculus, ‘they [the Gauls] cut off their heads and fasten them to the neccks of their horses. They hand over the blood-stained spoils to their attendants and they carry them off as booty chanting a paean over them and singing a hymn of victory. They nail up the heads on their houses just as certain hunters do when they have killed wild beasts. They embalm in cedar oil the heads of their most distinguished enemies and keep them carefully in a chest: they display them with pride to strangers, declaring that one of their ancestors or their father or the man himself refused to accept a large sum of money offered for this head. They say that some of them boast that they refused the weight of the head in gold.’ #Strabo repeats these details almost verbatim and claims that Posidonius had seen such heads displayed in many places and had at first been disgusted by the sight but later got used to it.

Lime-Washed Hair

Celtic warriors favoured fierce-looking hairstyles. Diodorus Siculus, along with other ancient authors, mentions how the Celts used to artificially ‘whiten’ their hair with lime water, allowing them to shape it so that it looked something like the mane of a horse. Warriors favouring this horse-mane hairstyle may have been trying to invoke the aid of the Celtic horse goddess Epona.

The Gauls are tall of body with rippling muscles and white of skin and their hair is blond, and not only naturally so for they also make it their practice by artificial means to increase the distinguishing colour which nature has given it. For they are always washing their hair in limewater and they pull it back from the forehead to the nape of the neck, with the result that their appearance is like that of Satyrs and Pans since the treatment of their hair makes it so heavy and coarse that it differs in no respect from the mane of horses

Diodorus Siculus, The Library of History, Book 5, Chapter 28

Historic References to Celtic Battle Tactics

We know relatively little about Celtic battlefield tactics. While individual accounts of battles recorded by the Romans exist and are even fairly thorough, they seem to have constantly sought to make the Celtic tribes out as barbarians. However this was not true, the Celts had a good understanding of battle tactics and often had a disciplined army.

Battle of the Allia (387 BC) – Use of Terrain

The Battle of the Allia was a battle fought c. 387 BC between the Senones – a Gallic tribe led by Brennus, who had invaded Northern Italy – and the Roman Republic. Livy descibes how the Gauls decisively outgeneralled the Romans at Allia, seizing a key hill and turning the flank.

The consular tribunes had secured no position for their camp, had constructed no entrenchments behind which to retire, and had shown as much disregard of the gods as of the enemy, for they formed their order of battle without having obtained favourable auspices. They extended their line on either wing to prevent their being outflanked, but even so they could not make their front equal to the enemy’s, whilst by thus thinning their line they weakened the centre so that it could hardly keep in touch.

On their right was a small eminence which they decided to hold with reserves, and this disposition, though it was the beginning of the panic and flight, proved to be the only means of safety to the fugitives. For Brennus, the Gaulish chieftain, fearing some ruse in the scanty numbers of the enemy, and thinking that the rising ground was occupied in order that the reserves might attack the flank and rear of the Gauls while their front was engaged with the legions, directed his attack upon the reserves, feeling quite certain that if he drove them from their position, his overwhelming numbers would give him an easy victory on the level ground. So not only Fortune but tactics also were on the side of the barbarians.

Titus Livius (Livy), The History of Rome, Book 5, Chapter 38

Battle of Sentinum (295 BC) – Testudo

Livy mentions the Celts when writing about the Battle of Sentinum (295 BC). A decisive battle of the Third Samnite War. A fairly disciplined form of combat, by any measure. Celts were known to lock shields in what the Romans described as a ‘testudo’ on the defensive. Once the Romans had adopted the Celtic Shield. for it is clear that a ‘testudo’ could not be achieved with the older Roman round shield or buckler.

The Gauls were standing in close order covered by their shields, and a hand-to-hand fight seemed no easy matter, but the staff officers gave orders for the javelins which were lying on the ground between the two armies to be gathered up and hurled at the enemy’s shield wall. Although most of them stuck in their shields and only a few penetrated their bodies…

Titus Livius (Livy), The History of Rome, Book 10, Chapter 29

Battle of Faesulae (225 BC) – Ambush

The Battle of Faesulae was fought in 225 BC between the Roman Republic and a group of Gauls living in Italy. A pan-Gallic army ever to march on Rome, with over 20,000 cavalry and 50,000 infantry in response the Romans drew together 150,000 soldiers with the assistance of their allies, the Sabines, Samnites, Lucanians and Marsi. The outnumbered Gauls were three days from Rome when they met the Roman  advanced force…

At sunset the two armies were in close proximity, and encamped for the night at no great distance from each other. After nightfall, the Celts lit their camp-fires, and, leaving orders with their cavalry to wait until daybreak and then, when visible to the enemy, to follow on their track, they themselves secretly retreated to a town called Faesulae and posted themselves there, their intention being to wait for their cavalry, and also to put unexpected difficulties in the way of the enemy’s attack. At daybreak, the Romans, seeing the cavalry alone and thinking the Celts had taken to flight, followed the cavalry with all speed on the line of the Celts’ retreat. On their approaching the enemy, the Celts left their position and attacked them, and a conflict, at first very stubborn, took place, in which finally the numbers and courage of the Celts prevailed, not fewer than six thousand Romans falling and the rest taking to flight. Most of them retreated to a hill of some natural strength where they remained.

Polybius, The Histories of Polybius, Book 2, Chapter 25

Battle of Telemon ( 225 BC) – Fine order of the Celtic host

Polybius tells us of the allied Gallic army at the battle of Telamon, when caught between two armies, formed up calmly and in good order facing both directions in a position which greatly impressed observers.

The Romans, however, were on the one hand encouraged by having caught the enemy between their two armies, but on the other they were terrified by the fine order of the Celtic host and the dreadful din, for there were innumerable horn-blowers and trumpeters, and, as the whole army were shouting their war-cries at the same time, there was such a tumult of sound that it seemed that not only the trumpets and the soldiers but all the country round had got a voice and caught up the cry. 

Polybius, The Histories of Polybius, Book 2, Chapter 29

Battle of the Sabis (57 BC) – Attacking the baggage train

The Battle of the Sabis, was fought in 57 BC in Northern France and Belgian, between Caesar’s legions and an association of Belgae tribes, principally the Nervii. Julius Caesar, commanding the Roman forces, was surprised and nearly defeated. Even Roman accounts acknowledge the Celts using complex tactics, such as the plan of separating legions by attacking the baggage train in the middle of Caesar’s column at the Battle of the Sabis.

And this was before any long term contact with Roman and other indigenous peoples amended the Celts’ ‘heroic’ approach to battle. Certainly, the berserker assaults were a characteristic of Celtic battle–but not to the exclusion of all else, nor were they necessarily “out-of-control” even when frenzied.

Certainly, the mindless frontal assault was not universal Celtic behaviour in battle. Unlike their western relatives, the Galatians calmly waited the Roman attacks in 189 BC, which was different from their ancestors only a hundred years before. Even the idea of a mindless, uncontrollable assault at first sight of the enemy, is belied by evidence.

The wild charges could be ‘controllable.’ The Galatian attack at Thermopylae is described thus: “They rushed at their adversaries like wild beasts, full of rage and . . . even with arrows and javelins sticking through them they were carried on by sheer spirit while their life lasted.” Yet Duncan says, ” . . .the Galatians kept up this almost berserk enthusiasm, despite making no headway, till their leaders called them off;” The end, ’till leaders called them off’ is an interesting one after describing the wild, animal-like fighting. Many descriptions make the frenzied Celts sound as though they were on a leash. For example, we see none of this uncontrollable behavior in the descriptions of Gauls fighting with/for the Carthaginians, even when deployed as independent units during any of the Punic Wars–and a number of these troops were tribes from the relative primitive Alpine regions.

Though the Celts fought mainly with infantry, cavalry forces were used by many of the tribes. In most cases, these cavalry forces were most likely made up simply of horse-mounted infantrymen. Many Celtic archaeological sites, however, have yielded remains of chariots, which would have been more effective in most battles and would also have required somewhat more skilled handling to use to their fullest advantage. Roman accounts indicate an intriguing tactic employed by the Celts in their chariot warfare of using chariots to deposit soldiers riding on board into enemy ranks. Though such use of chariots was not unheard of in the ancient world, it was much more standard for soldiers to remain on board the chariot while the charioteer drove it through the enemy ranks, rather than jumping off to engage on the ground.

In many cases, warfare would become the occupation of entire tribes for periods of time. In these instances, the tribes would actually find themselves moving with their armies, as in the case of Boudicca’s army or the Helvetii of Gaul, both of which moved with far larger numbers of non-combatants than actual warriors. For this reason, large numbers of four-wheeled wagons would often be brought along on campaigns, as sufficient food to sustain both the army and non-combatant population would be required. This practice proved to be detrimental to Celtic armies in many instances, particularly in their fights against the Romans. Celtic armies, when burdened with thousands of people who were not warriors, often could not move as quickly as the highly trained Roman legions. As can be seen in the case of the Battle of Watling Street, this massive group of non-military personnel could also restrict the movements of the Celts on an active battlefield.

In Celtic defensive actions, fortifications were always an important element. Not having the same heavy shields and armor as the Romans equipped their legions with, the Celts would have had a very difficult time creating a defensive line on an open battlefield that could effectively stand against the Romans. Celtic hill forts and the larger oppida, therefore, took on a special significance in places the Celts wished to defend. Under most circumstances, however, Celtic armies seem to have preferred offensive campaigns, resorting to defensive positions only when no other option readily presented itself.

A common custom among Celtic tribes, according to Roman sources, was to cut off the heads of fallen enemies for display in their own communities. Celtic religious custom seems to have held that the head was the part of the body that housed the soul or spirit, meaning that ritual decapitation allowed the Celts to bring the spirits of their foes back with them as captives. An account left to us by Diodorus Siculus indicates that, when a battle was finished, a victorious Celtic army would decapitate the bodies of its enemies and hang them around the necks of horses for the journey back to their settlement. Unlike most of the more barbaric practices of the Celts that are mentioned by the Romans, there is significant archaeological evidence to suggest that headhunting was a real custom of the Celtic tribes, and Roman accounts are corroborated by Greek writers, who were generally less biased against the Celts.

Classical References to Celtic Warfare

The classical authors who describe Celtic warriors at length are the following:

  • Polybius. Histories, ii, chapters 14-31 (Greek).
  • Diodorus Siculus. History, v, chapters 25-32 (Greek).
  • Strabo. Geography, iv, chapters 1-4 (Greek).
  • Caesar. De Bello Gallico, vi, chapters 11-28 (Latin). Expeditions to Britain, iv, 20-36; v, 8-23.
  • Tacitus. Agricola (Latin).
  • Athenaeus. Deipnosophistae, iv, chapters 34. 36, 37, 40, 49 (Greek).
  • Pausanias. Guide to Greece, x, 19-23 (Greek).