Telamon War (225-222 BC)

The Telamon War (225-222 BC) saw the Romans defeat the last major independent Gallic attack on Rome at Telamon in 235 then go on to establish their dominance over the Gauls of northern Italy, only to have all of their achievements collapse when Hannibal crossed the Alps at the start of the Second Punic War.

The Romans began to expand into Gallic territories on the Adriatic coast after the Gallic War of c.284-283. This had seen them break the power of the Senones, and establish a colony at Sena, on the coast north of Ancona. In 268 the Romans had created a new colony at Ariminum (modern Rimini), further north along the coast from Sena, in an area that had been in Gallic hands until they were expelled by the Umbri. The next clash came in 238-236 when the Romans fought against an alliance led by the Boii (Boian War). The Romans hadn’t performed terribly well during this war, which came at the same time as their initial campaigns on Sardinia and Corsica and an invasion of Liguria. However the Gallic alliance led by the Boii had fallen apart and the allies had fought amongst themselves, suffering heavy losses that left the Boii so weakened that they had to surrender some of their lands to the Romans.

In 232 BC what to do with the newly conquered areas caused a political controversy in Rome, which also raised tensions with the Gauls. The Tribune C. Flaminius put forward a proposal to expand the long established practise of distributing conquered lands nearer to Rome to the Roman population to the areas around Ariminum and Picenum. These areas were still largely populated by Gauls, who would thus have been dispossessed. The proposal also caused controversy in Rome, where the Senate had generally been responsible for establishing colonies as the Republic expanded further away from Rome. It isn’t entirely clear who ended up in charge of the new settlement programme, but it does appear to have happened.

War nearly broke out in 230 BC, although the exact details of what happened are obscured by a problem with our main source for these events, Zonaras. The Romans were worried that the Boii were offering a large number of captives for sale (presumably captured during unrecorded battles with other Gallic tribes), and forbade anyone giving gold or silver to a Gaul, presumably to stop them hiring mercenaries. The Romans then sent both of the consuls for the year towards Liguria, but while they were on their way another power, fearing that the Romans were really about to attack them, raised an army and prepared to march on Rome. The Consuls diverted their army to march against the new foes, who lost their nerve and met the Romans peacefully. The Romans were also clearly not ready for war, and the Consuls claimed that they weren’t attacking this power, but were simply heading towards the Ligurians. The surviving text of Zonaras says that this power was Carthage, but that doesn’t make sense, as the Carthaginians had no foothold in Italy. The most likely candidate is the Boii.

In the aftermath of this incident the Romans clearly felt secure enough to send an army overseas, as in 229 they crossed the Adriatic at the start of the First Illyrian War. However over the next few years the Gauls of northern Italy began to create a new alliance to take on the Romans. This was led by the Boii, who inhabited an area on the lower Po around Bologna, and the Insubres, who was based in the area around Milan. They then recruited mercenaries from Transalpine Gaul, convincing Kings Concolitanus and Aneroestus of the Gaesatae to join them. Gaesatae translates as spear carriers, and indicates that these were groups of mercenaries. According to Polybius they came from the Alps and along the Rhone. In his account of the battle of Telamon Polybius also mentions the Taurisci, from the ‘slopes of the alps’. Later sources only mention the Insubres and not the Boii, suggesting that the Isubres were the most important element of the alliance.

By 228 the Romans appear to have become alarmed by the activity to their north. According to Plutarch and Zonaras they found an oracle in the Sibylline books which said that the Gauls and Greeks would occupy the city. In order to prevent this the Romans carried out the first known example of human sacrifice in Roman history, burying alive two Gauls and two Greeks (in each case a man and a woman) in the ‘forum boarium’, a cattle-market. On a more practical note they doubled the number of Praetors, which gave then a bigger pool of commanders with full Imperium. This may also have been triggered by the expedition across the Adriatic and the conquests of Sicily, Sardinia and Corsica, each of which made it more likely that Rome would need to field several armies at once. For three years, 228 to 226, we have no record of any major conflicts involving the Consuls, a most unusual gap in this period. Polybius records that the Romans spent the period raising legions and gathering stores of grain and other supplies, and repeatedly marching to their borders as if they had been attacked – either to train the new legions or because of false reports of a Gallic invasion.

In 226 the Romans agreed to the Ebro Treaty with Hasdrubal in Spain, agreeing that the River Ebro would be the dividing line between their spheres of influence. At the time this treaty was probably intended to lower the risk of a war in Spain, although in the end it helped contribute to the outbreak of the Second Punic War. Nearer to home the Romans were able to form an alliance with two Gallic tribes in the north-east of Italy, the Veneti and the Cenomani, probably in 225. The Romans also formed two new reserve legions in the south of their growing Empire, one on Sicily and one at Tarentum.

The Romans were alerted to the imminent invasion when the Gaesatae began to cross the Alps from Transalpine Gaul into Cisalpine Gaul. Our sources differ on the size of the Gallic army. Polybius says that the threat from the Veneti and Cenomani forced the Insubres and the Boii to leave troops behind to deal with this threat, although he doesn’t say how many. This still left them 50,000 infantry and 20,000 cavalry for the main invasion force. Diodorus gives a much larger figure of 200,000 for the Gallic army.

Polybius gives us a detailed breakdown of the forces that the Romans were able to gather to deal with this threat. Five separate armies were formed.

The two consuls for the year, L. Aemilius Papus and C. Atilius Regulus, each commanded four legions of Roman citizens, each containing 5,200 infantry and 300 cavalry, along with an allied force of 30,000 infantry and 2,000 cavalry. That gave each Consul 50,800 infantry and 3,200 cavalry. Early in 225 C. Atilius Regulus was sent to Sardinia, possibly to deal with a revolt that had broken out a year or two earlier, while L. Aemilius Papus was sent to Ariminum, on the Adriatic coast, because the Romans believed that the Gauls would attack on the eastern side of the Apennines.

The Etruscans and Sabines provided 50,000 infantry and 4,000 cavalry, and were placed under the command of one of the praetors. This army was placed on the frontiers of Etruria, presumably west of the Apennines.

The fourth army was made up of a combination of 20,000 Umbrians and Sarsinates from Rome’s possessions in the Apennines, combined with 20,000 Veneti and Cnomani. This army was placed on the frontier of Gaul, and given the task of invading the territory of the Boii and prevent them taking part in the main campaign. If this army was indeed united as a single force, it may have started the war on the lower Po, where Roman territory came close to that of the Cnomani.

The fifth army was a reserve force at Rome, made up of another 20,000 Roman citizen infantry and 1,500 cavalry and 30,000 infantry and 2,000 cavalry.

Each of the Roman armies was thus slightly smaller than the combined Gallic force, but if any two of them were able to combine then the Gauls would be badly outnumbered.

The Campaign of 225 BC

The Romans had dangerously misjudged the Gallic plan. At the start of the campaign the Gauls crossed the Apennines and invaded Etruria. They were able to bypass the Praetorian army that had been posted on the border of Etruria and marched towards Rome, devastating the country as they went. Although the Gauls had got past the first Roman army, the net was soon closing around them. The praetor gave chase, and followed them towards Rome. Aemilius led his army back from Ariminum, and must have reacted pretty quickly, for he was also soon on the scene. Atilius Regulus was able to return to the mainland, landing somewhere to the north of Pisa. This suggests that either the Romans had moved very quickly, or the Gauls had moved fairly slowly, pillaging as they went. The aftermath of the first battle of the campaign would suggest the second alternative.

When they were at Clusium, only three days from Rome, the Gauls learnt that the Praetor’s army was close behind them. They turned back and defeated the Praetor near the town of Faesulae. The only known town with this name is about 80 miles north of Clusium, suggesting that the Gauls were aware of the approaching army while it was some way to their north. Polybius says that around 6,000 Romans were killed (in this case Etruscans and Sabines) and most of the survivors took refuge on a nearby hill. Just as the Gauls were about to besiege the survivors,  the leading elements of Aemilius’s army reached the battlefield.

The Gauls held a war council at which Aneroestus, one of the leaders of the Gaesatae, convinced them to retreat north with the booty they had seized on the way south, which included a large number of slaves and cattle, then turn back to deal with the Romans. If Polybius’s figures are correct, then the Gauls were probably outnumbered by the combined Roman forces – the Consul’s army wasn’t that much smaller than the original Gallic force, and if only half of the defeated army had stayed, then that would still have been another 25,000 men.

The Gauls broke camp and headed north along the coast. Aemilius decided to follow them north, but not to risk a battle until he found a suitable occasion to inflict damage on them. At the same time Atilius Regulus had landed further north, and was marching south.

The three armies collided at Telamon. The two Roman armies were marching towards each other, but weren’t in contact with each other. Atilius, marching south, captured some of the leading Gallic troops, and discovered that the main army was close behind. He also spotted a hill that overlooked the route the Gauls would have to take and decided to lead his cavalry onto that hill, leaving his legates to command the infantry with orders to continue advancing as long as they remained in good order. When the Gauls saw Roman cavalry on the hill they initially assumed that part of Aemilius’s army had managed to outflank them, and sent a mixed force of cavalry and light infantry to clear the hill. At first this battle went the way of the Gauls. They captured prisoners from whom they discovered that the second Roman army was in front of them, and even killed Atilius. However Aemilius’s army was close enough to see the fighting and he sent his cavalry to join in. The combined Roman cavalry forces eventually won this first part of the battle and occupied the hill.

The lack of coordination between the Roman armies gave the Gauls time to prepare for the upcoming battle. The Gaesatae and Insubres faced Aemilius, with the Gaesatae choosing to fight naked. The Taurisci and Boii faced towards Atilius. The battle began with a Roman volley of javelins, which inflicted heavy losses on the vulnerable Gaesatae, who broke under the pressure. However the remaining Gauls stood and fought, and the resulting infantry clash was a hard fought stalemate until the Roman cavalry attacked from the hill. At this point Gallic resistance collapsed, and they suffered a crushing defeat. Polybius reports that 40,000 were killed and 10,000 captured. Concolitanus was taken prisoner and Aneroestus killed himself to avoid the same fate. No more than 20,000 Gauls can have escaped, assuming the army was still close to full strength.

In the aftermath of the battle Aemilius sent the booty captured during the battle back to Rome, and arranged to return the Gallic plunder from Etruria to its original owners. He then advanced up the west coast into Liguria, from where he invaded the Boian lands along the Po. The Boii and the Insubres had left part of their armies at home to watch the Veneti and Cenomani, but there is no mention of any resistance to Aemilius, who was able to pillage the Gallic lands. This campaign may have lasted into the following year, as Diodorus reports that Aemilius was proconsul for at least part of the campaign.


224 BC

In 224 BC Aemilius returned to Rome where he celebrated a hugely symbolic triumph, which included taking the Gallic prisoners onto the Capitol, the scene of the possible last defence of Rome during the Gallic sack of c.387 BC. Telamon and the invasion of northern Italy that followed marked the moment when the balance of power finally changed. Although the Gauls would take part in many more battles against the Romans, they would no longer be a direct threat to Rome in their own right, but either be fighting with allies (most famously Hannibal) or against Roman invasions of Italian Gaul.

In the aftermath of the crushing victory at Telamon the Romans decided to invade Cisalpine Gaul. Both consuls for the year, T. Manlius Torquatus and Q. Fulvius Flaccus, were serving for a second time and had previous command experience. Both  took part in the campaign, but sadly we have very little detail of what happened, and our sources don’t entirely agree on what happened. Polybius, the earliest surviving source, says that the Romans were easily able to force the Boii to submit to Rome, but that heavy rains and an epidemic mean that the rest of the campaign had ‘no practical results’. Orosius, writing much later but possibly based on the lost books of Livy, records that the two consuls were the first to lead Roman legions across the Po, where they defeated the Insubri, killing 23,000 and capturing 6,000. The Periochae of Livy has the Romans crossing the Po and defeating the Insubri, but could be dated to either 224 or 223 BC. Neither consul was awarded a triumph for 224 BC, which would suggest that they didn’t fight any major battles, but they were out of Rome when the Consular elections for 223 were held, forcing the Romans to appoint a Dictator to hold the elections. Polybius doesn’t actually say that the two consuls didn’t cross the Po, and the scale of any fighting may well have been exaggerated by the time Orosius was working, but we can’t be sure if they crossed the Po or not.

223 BC

We can be more sure for the following year. The consuls for 223 BC were C. Flaminius and P. Furius Philus, both consuls for the first time. According to Polybius they advanced through the territory of the Anares, who inhabited an area on the south bank of the Po to the west of the Boii and Insubres. They probably reached that area by marching through Liguria, as P. Furius was awarded a triumph for fighting the Ligurians in 223. The Romans then crossed into Insubrian land near the junction of the Po and the Adda (between Piacenza and Cremona). The Insubres inflicted some losses on the Romans both as they were crossing the river, and when they camped on the north bank. The Romans remained in place for an unknown period, then agreed a truce with the Insubres and returned to the south bank. The Romans then advanced east along the south bank of the Po into the lands of the Cenomani, their allies in 225. The two forces united and invaded Insubrian land from the east. The Insubres gathered together 50,000 men, and attacked the Romans at a river, possibly the Clusius. Although they fought without their Gallic allies, the Romans won another major victory.

This battle was somewhat overshadowed by events back in Rome. Flaminius had been a controversial Tribune of the Plebs and had clashed with the Senate over the distribution of lands taken from the Gauls in earlier wars. Now his opponents began to claim that a series of bad omens seen in Rome meant that the consuls had been elected inauspiciously. The Senate sent letters summoning the two consuls back to Rome and ordering them not to engage in combat until the case had been judged. These letters arrived just before the battle against the Insubires, but the Consuls didn’t read them until after the fighting was over.

After the battle the Consuls disagreed on what to do. Flaminius wanted to continue the campaign and ignore the order to return to Rome, but Furius threatened to split the army and march off without him. Flaminius’s men feared the results if they were left along, and were able to convince Furius to stay in the area for a few days more, but not to take an active part in the campaign. Flaminius’s army laid waste to the nearby area, issuing the spoils to his soldiers to win their support. The two consuls then led their army back to Rome.

After their return to Rome both Consuls were awarded a triumph for the victory of the Gauls, and Furius a triumph for his victory over the Ligurians. However our sources give rather different accounts of how the Roman people reacted. According to Zonaras, the Senate charged both Consuls with disobedience, but the populace forced the Senate to allow them to celebrate a triumph. According to Plutarch the people refused to meet Flaminius, almost refused to allow him a triumph and forced him to resign as Consul after his triumph.

222 BC

Once again the consuls for 222, M. Claudius Marcellus and Gn. Cornelius Scipio Calvus, were first time consuls, and we know nothing about their previous military experience. After their election they will have been expecting to lead a new army against the Insubres, but early in the year the Insubres sent ambassadors to Rome to sue for peace. The new consuls convinced the Senate not to make peace. The Insubres then recruited another 30,000 Gaesatae, from Transalpine Gaul, and prepared to meet the Roman attack. Plutarch gives a different account, with the Senate accepting the peace offer, but the Gaesatae breaking the truce.

This time the Romans had no trouble crossing the Po, and laid siege to the city of Acerrae (probably near modern Pizzighettone on the River Adda). The Roman positions around the city were too strong for the Gauls to attack, so instead they crossed into the territory of the Anares, Rome’s Gallic allies, and laid siege to Clastidium (Casteggio), about 34 miles to the west of Acerrae.

The Romans reacted by splitting their forces. Most of the infantry and two thirds of the cavalry stayed with Cornelius Scipio at Acerrae, while Marcellus was given the rest of the cavalry and 600 light infantry to chase the Gauls heading for Clastidium. The two forces clashed near Clastidium, in a battle that saw Marcellus win the spoila opima for killing the Gallic king Virdomarus in single combat.

While Marcellus was dealing with this threat, Cornelius Scipio was able to capture Acerrae. He then followed the retreating Gauls north-west to Mediolanum (Milan), which was their chief city. The Gauls didn’t react, and Cornelius Scipio decided to return to Acerrae. Only then did the Gauls attack, and for some time the Romans were under some pressure before eventually rallying and winning the day. Soon after this Mediulanum was captured, although out sources disagree on exactly how and who should be given the credit for it. The remaining Insubres chiefs submitted to the Romans, effectively ending the war that had begun in 225 BC.


In the aftermath of their victories over the Boii and Insubres, both tribes had to acknowledge Roman hegemony. Their eastern neighbours, the Cenomani and Veneti, were now Roman allies. The Romans continued to campaign in the north, conquering Istria in 221 and expanding into the Alps in 220. Early in 218 the Romans founded new colonies at Placentia and Cremona on the Po, and this triggered another clash with the Gauls. The two colony sites were over-run, and the Praetor Lucius Manlius suffered a defeat in woods near Mutina. However the situation in the north of Italy were about to be transformed. While the Romans were attempting to restore the situation on the Po, Hannibal was on his way from Spain. Late in the year he crossed the Alps and entered northern Italy. Unsurprisingly many of the Gauls soon sided with Hannibal, especially after he began to win his early victories over the Romans, and it would be some time before Rome would secure her conquest of the Po valley. Thousands of Boii and Insubres were part of Hannibal’s army at the battle of Cannae, one of the worst defeats in Roman history.

Rome Spreads Her Wings - Territorial Expansion between the Punic Wars, Gareth C. Sampson. Focuses on Rome's other wars in the period of the first two Punic Wars, including the first expansion east across the Adriatic into Greece and the Balkans and the conquest of Gallic northern Italy. This is a difficult period, with limited sources as ancient authors either concentrated on the more glamorous wars against Carthage, or have been lost to us. Sampson does a good job of guiding us through the difficult sources for this period, often providing alternative versions of key events, complete with their supporting sources. A useful book that helps fill a gap in the military history of Rome [read full review]
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How to cite this article: Rickard, J (28 November 2022), Telamon War (225-222 BC) ,

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