“Roman Hoplites defeated by Celts, fourth century BC”, Richard Hook

390 BC Rome is invaded and conquered by the Celtic Gauls; quacking geese on Capitoline Hill warn of the impending attack.

The battle on 18 July was a disaster of some magnitude for the Romans; 18 July, dies Alliensis, was labelled a black day, dies ater, which darkened the memories of Romans for many years to come. The enemy was foreign, the first time Rome had been in conflict with non-Italians. The Gauls had a very different fighting style and they had very different objectives from the Italians. They were frightening: clamorous, colourful, they wielded strange weapons and wore unfamiliar armour. Alarmingly for the Romans, some of them even fought naked – to avoid their clothing snagging on hedgerows. The battle, and the run up to it, exposed complacency and arrogance on the part of the Romans: centuries of military success were to come to an abrupt and shocking end, which compromised the security of the very city of Rome and all the military achievements won so far.

Who were these Gauls and where did they come from? The Gauls in question were the Senones, a tribe which had crossed the Apennines in search of trade and new land to settle. They, and other Gauls, were massing in Cisalpine Gaul – that part of Italy immediately south of the Alps. They traded with towns such as Massilia and Etruria, which drew them in successive waves over the mountains from parts of what is now France, southern Germany, Switzerland, Austria and the Czech Republic into northern Italy and the Balkans via the rivers Rhône, Seine, Rhine and Danube, from about 500 BC. Conflict was inevitable: around 400 BC, the Insubres occupied Lombardy and took Mediolanum (near Milan) in 396 BC; next came the Boii who crossed the River Po and settled in Bononia (Bologna). The Senones audaciously penetrated further south; they drove out the Umbrians and established the ager Gallicus on the east coast of Italy between Ariminum and Ancona, then founded Sena Gallica (Sinigaglia), which became their capital. Etruscan towns further south, such as Marzabotto, were taken, probably by the Boii. Significantly for the Romans, Gauls were selling their services as mercenaries to southern Italian towns and tribes, and to various Hellenistic powers in the eastern Mediterranean. This entailed their transit down through the length of the Italian peninsula en route to rendezvous with their paymasters and warlords in their various theatres of war.

The Gauls, not surprisingly, usually received a bad press from Roman writers: Livy says that they came from the very ends of the world. Strabo describes them as ‘war-mad’, quick to fight but not malicious – a description at odds with his later report of their enthusiasm for head hunting and the use of other body parts hacked from the vanquished as battle trophies. He emphasizes their naivety in strategy and tactics – something survivors of the sack of Rome may have found difficult to reconcile with their experience of events. Diodorus Siculus details the Gauls’ military equipment or, in some cases, the absence of it amongst those relying on nature’s protection alone; he also describes their skilful use of the chariot in battle – which their Celtic cousins in Britannia successfully deployed when facing Julius Caesar’s invasion.

In the early fourth century BC, the Senones finally reached Clusium (Chiusi) in the Etruscan province of Siena and made camp there. We can dismiss the story that the Senones were invited by Arruns of Clusium to assist him in taking revenge on his wife’s lover, the powerful Lucomo. The Senones began to negotiate for land rights; understandably, the Clusians felt threatened by the terrifying sight of hordes of strange-looking, weird warriors at their gates and called for help from Rome. Rome, however, was somewhat weakened by recent wars; they had no obligations to Clusium and half-heartedly sent a delegation of three ambassadors, the Fabii brothers from the powerful patrician family, to negotiate. The Fabii counselled peaceful negotiation, warning the Senones that Rome would be obliged to help Clusium should it be threatened. According to Livy, however, ‘The envoys behaved more like savage Gauls than Romans.’

The Gauls gave an ultimatum: a portion of the Clusium lands, or war. When the negotiations came to nothing, the Clusians attempted to force the Senones off their land. The ambassadors got involved and, in so doing, according to Livy, ‘broke the law of nations’ – ius gentium – when they disregarded their oath of neutrality as ambassadors ‘and took up arms’ against the Senones. Things got completely out of hand when Quintus Fabius killed one of the Gallic chieftains. When Quintus Fabius proceeded to strip the Gaul of his armour, the outraged Senones withdrew to take stock, only too aware that the sacred trust of the ambassador had been violated. The Romans had clearly not reckoned on the fact that the Gauls took their law and diplomacy very seriously. The issue was not now with the Clusians but with Rome.

The Senones despatched their own ambassadors to Rome, demanding that the Fabians be handed over to them so that justice might be done. Many Romans were sympathetic, and agreed that there had been a breach of the law of nations. Plutarch adds that the fetiales – that sacred body of military diplomats and envoys – were keen for Quintus Fabius to be punished. The Senate, although fully aware that surrendering the Fabii was the right way to go, were swayed by the people and refused to hand them over. Livy records the perversity of the situation and how Rome added insult to injury, or rather murder, in his report that two of the Fabii, far from being punished, were actually appointed for the coming year as military tribunes with consular powers. The Gauls were understandably incandescent and left, threatening war with Rome.

The 130km march of the Senones from Clusium to Rome to take revenge was quite remarkable and further reinforced their claim that they desired to occupy land by agreement, and peacefully at that. According to Livy, the Senones left the peoples they passed en route unmolested and did not plunder their lands. It was with Rome, and with Rome alone, that they had an issue.

The Senones advanced with amazing rapidity and on 18 July confronted the Romans about 18km north of the city, at the River Allia, the Fosso della Bettina, a small tributary of the Tiber, north of Fidenae. Livy predicts the immense calamity that was about to unfold: ‘When such a mass of evil was looming,’ incredulous, that the Romans had not seen fit to appoint a dictator – so often their saviour in battles past – and oblivious to the fact that this was a new kind of enemy, prone to ferocious anger, with unpredictable ways and unfamiliar tactics, cacophonous and full of verve. The Gauls were obviously no Italians. Plutarch describes the naivety of the Roman army and, crucially, the fact that the hubristic Romans omitted to consult the gods or the augurs in advance of the battle.

The Roman forces under Q. Servilius Fidenas, Q. Sulpicius Lagus, and P. Cornelius Maluginensis numbered 15,000, made up of Romans and Italian allies; the Gauls, led by a chieftain called Brennus, were at least double that strength, anything up to 70,000 strong. Hopelessly unprepared and seriously outnumbered, the Romans kept their centre dangerously thin. They were cut down in their droves: the Roman reserves, positioned on higher ground, were routed without a Roman sword being drawn when Brennus attacked these first and slew them in flight; predictably, the centre then collapsed; the left wing was destroyed and those that could escape swam the river or drowned, dragged under the water by their cumbersome kit. Diodorus adds that the Gauls picked off the Romans with their javelins; the Romans were at the mercy of the long-reach Gallic swords. Survivors retreated to the town of Veii, a former enemy settlement laid waste by the Romans. The soldiers on the left fled back to Rome to take refuge on the Capitol, carelessly leaving the city gates open and undefended. Livy says that the Gauls were dumbstruck (Gallos obstupefactos) at the ease of their victory and feared a trap. There was no trap.

Diodorus melodramatically records that the Gauls spent the next day cutting off the heads of the Roman dead. Reassured that they had won the day, the Gauls heaped up the discarded Roman weapons and moved on Rome. Incredulously, scouts confronted a city with its gates ajar, no sentries on duty and with no soldiers manning the walls. The Roman citizens inside had no reason not to believe that those who had taken refuge in Veii were also dead, a misjudgement which served only to amplify their lamentations. They were also terrified, their fear heightened by the baying on the other side of the walls. Eventually, the Gauls entered the city by the Colline Gate. The surviving Romans, under the command of Marcus Manlius Capitolinus, had sensibly decided against defending the city and, as we have seen, ignominiously took refuge with women and children on the Capitol, where they hoped to make a final stand. The elderly were left down in the city so as not to be a burden to the fighters on the Capitol: Livy gives a wretched description of the older, non-combatant, men and the wailing women who were denied a place on the Capitol. Excavations have revealed contemporary burn marks in the Forum and on the Palatine which indicate extensive fires in Rome around this time.

The Roman state was in jeopardy. The Vestal Virgins and their essential flame, symbols of the sanctity, survival and well-being of Rome, were in peril, but they escaped to Caere with the flamen Quirinalis and other sacred objects. What they could not carry, the Vestals buried in earthen jars next to the Flamen’s house; it was forbidden to spit on that sacred ground thereafter. Plutarch tells that it was imperative not to let the flame fall into enemy hands or to allow it to expire, such was the awe in which it was held by the Romans. A plebeian, Lucius Albinus, was fleeing the city along with thousands of other refugees, his wagon laden with his family and everything he owned. Livy tells the tale:

they were seen by L. Albinius, a Roman plebeian who with the rest of the crowd who were unfit for war was leaving the city. Even in that critical hour the distinction between sacred and profane was not forgotten. He had his wife and children with him in a wagon, and it seemed to him an act of impiety for him and his family to be seen in a vehicle whilst the national priests should be trudging along on foot, bearing the sacred vessels of Rome. He ordered his wife and children to get down, put the Virgins and their sacred burden in the wagon, and drove them to Caere, their destination.

Indeed, Lucius Albinus as much as anyone could lay claim to being the saviour of Rome when he dutifully and selflessly brought the sacra to safety, preserving the very symbol of the security and sanctity of the city. Rome was surely doomed if the Vestal flame spluttered and went out.

Thousands of plebeians, refugees in their own city, likewise streamed out of Rome and headed for the relative safety of the Janiculum – a scenario repeated time and time again down the years throughout history to the present day, Syria being just the current example. Nearer home, the inhabitants of British cities echoed the fate of the Romans during the blitz, when they, the ‘trekkers’, left their homes each evening and took refuge in the countryside to escape that night’s incendiaries and high explosive bombs.

Elderly senators were prepared to die for Rome in a kind of devotio; they proudly took up positions outside their homes on ivory chairs, dignified, statue-like and stoic, to await their fate. The Gauls found them, a surreal sight, dressed in their finery and sporting their military medals: at first they were mesmerized, but astonishment soon turned into slaughter when one of the Gauls stroked the long beard of Marcus Papirius; Marcus Papirius responded by striking him with his staff, with predictable consequences.

The Gauls then proceeded to sack the city, showing neither quarter nor mercy. According to Plutarch, ‘the Gauls inflicted every outrage upon the city, and put to the sword all whom they captured, men and women, old and young alike.’ But Livy records that it was nowhere near as bad as it might have been; the Gauls seemed to have shown some restraint. Neverthless, nothing was going to stop them preparing for an assault on the Capitol. The Romans, however, had gravity and momentum on their side: their first sally against the clambering Gauls effectively sent them hurtling back down the hill. The Gauls did not repeat the assault but prepared for a siege. The siege, however, was embarrassed somewhat by the fact that the Gauls had foolishly burnt all the grain when they torched the city, and were compelled to go out to forage for more. This gave the Romans invaluable time.

Servius, in his commentary on the Aeneid, tells how during the siege women banded together and donated their gold and hair to make bowstrings for the Roman archers.

But Rome needed a saviour. As it happened, a disaffected Marcus Furius Camillus was in exile in nearby Ardea. Acting independently, during a night raid, he and a motley army slaughtered sleeping, inebriated Gauls who had been enjoying the spoils of victory. Similar butchery was visited on opportunistic Etruscans near Veii for failing to assist the Romans in their hour of need.

Camillus could not continue to act as a maverick commander and sought to make his position official. Once the necessary formalities with the Senate were concluded, he was free to rouse the Ardeans to assist the Romans bottled up on the Capitol. As it happened, Camillus was always an obvious choice: a seasoned general, he had also commanded many of the Romans now in Veii and on the Capitol. Camillus himself had earned four triumphs, was dictator five times and became known as the Second Founder of Rome; in short, a highly successful, swashbuckling commander. He was, however, later convicted of embezzling booty and went back into exile.

Camillus refused an impromptu generalship but accepted a one-year dictatorship in absentia with the task of ridding Rome of the Gauls. He recruited an army of 12,000 men from Veii to help him. In the meantime, the Gauls made a daring assault on the Capitol which took the Romans by surprise. The plan was hatched when the Gauls spotted the foot and handprints left by the brave Pontius Comitius who had acted as envoy between the Romans in the Senate, wending his way through the enemy lines to secure the approval of the Senate for Camillus to be made dictator. According to legend, the sacred geese of Juno heard the assailants (the guard dogs did not, it seems) and by their din alerted the consul Marcus Manlius. Manlius promptly sent a Gaul toppling down the cliff, creating a kind of human avalanche, taking all his comrades tumbling down with him. Manlius was rewarded with gifts of food and drink – an exceptional gesture in view of the prevailing shortages and imminent famine on the Capitol – while one of the negligent guards was thrown over the cliff to his death, more militare, the way the army does.

The Gauls were now camped in a valley where conditions were less than salubrious: it was dry, hot and dusty – the complete antithesis to the climate and environment they were used to back in Gaul. They were soon plagued by an epidemic, exacerbated, no doubt, by the putrefying corpses of the unburied dead; the corpses were later burnt on mass pyres. Seven months had now passed and famine was gripping the Romans on the Capitol, but still Camillus was nowhere to be seen, busy as he was recruiting and training an army capable of dealing with the Gauls. The Romans could either capitulate or negotiate terms. The Senate agreed to talks led by Brennus and Quintus Sulpicius.

Brennus negotiated an end to the siege whereby the Romans agreed to pay 1,000lb in gold. Brennus, however, acted duplicitously when he used heavier weights than standard when weighing out the gold. The Romans protested, only to have the Gaul angrily throw his sword and belt on the scales and shout insultingly in Latin, ‘Vae victis!’ – ‘Woe betide the vanquished!’ Meaning, the winner takes it all. At this point, Camillus arrived back with his army; he entered the negotiations and placed his sword on the scale, exclaiming, ‘Non auro, sed ferro, recuperanda est patria’ – ‘You only win back this country with iron, not gold.’ The deal was annulled and the gold was taken back. Just as significantly, this was a virtual declaration of war: two battles ensued, the second, decisive one on the road to Gabii. Camillus routed the Gauls and returned triumphant to Rome; it was at this point that he was hailed a second Romulus, a second founder of Rome.

The battle at the Allio and the subsequent sack and siege of Rome saw the Romans displaying breathtaking military naivety, diplomatic arrogance and impiety; they were within an ace of losing everything they had gained since 753 BC and, had it not been for the Gauls sticking to their original, true objectives – simply to settle new lands – they might well have done. The Romans could be forgiven for their military ingenuousness: they had never endured a foreign invasion before and they, for the most part, had never before encountered a Gaul, a barbarian force. How could they know how best to repel such an extraordinary invader? Their tactics at the river were, admittedly, hopeless; perhaps another example of complacency and arrogance. Their own national pride and haughty feelings of military superiority cost them dearly.

The colourful episodes peppering the descriptions of the Battle of the River Allia and the sack of Rome are, of course, legends. They are embellishments, fictional anecdotes designed to conceal or mitigate the scale of the disaster and to restore Roman pride with pietatis exempla et fortitudinis – examples of dutifulness and bravery. The story of the Vestal Virgins and the handcart, and the tale of Roman women giving gold to help finance the Roman cause, the geese, brave, stalwart Marcus Papirius and his colleagues and the valour of Pontius Comitius were all invented to salvage Rome’s reputation for military might in those times of extreme danger. Even Camillus’ intervention has been called by Cornell ‘the most artificially contrived of all Rome’s heroes.’

If the Romans were complacent before and during the battle, there was certainly no evidence of this in the immediate aftermath. Camillus effectively saved Rome a second time when he helped scotch a move to relocate the devastated capital to the ghost town that was Veii. Rome would remain the capital city. Camillus took the initiative in a number of reforms. Unusually, Camillus did not resign the dictatorship at this point: he considered that there was still much work to done in saving Rome. His first move was to rebuild or restore each of the sacred buildings wrecked by the Gauls, aided by consultation of the august Sibylline Books – only ever consulted in times of dire emegency. Caere, the ultimate destination of the Vestal flame and the Vestals on the cart that fateful day, was honoured, while the Capitoline Games were set up to celebrate Jupiter, saviour of the city. The women who gave the gold to pay off the Gauls were rewarded by having orations delivered at their funerals, hitherto an honour reserved for men – a small but important step forward for Roman women.

Camillus proceeded to rebuild the city of Rome. Sadly, according to Livy, it was a bit of a botch, with crooked roads, errant sewers and unrestricted, indiscriminate plundering of timber and stone for haphazard housing developments. According to Plutarch, however, things were not all that bad: ‘within a year’s time, it is said, a new city had arisen, with walls to guard it and homes in which to dwell.’

Defensively, the tufa Servian Wall – murus Servii Tullii – may well have been constructed around this time, up to 10m high in places, 3.6m wide at its base and 11km long, with sixteen gates. The wall served its purpose well during the Punic Wars. Surviving sections can be seen outside Termini Railway Station in Rome, including a small piece in the McDonald’s at the station, and on the Aventine, where it incorporates an arch for a catapult from the late Republic.

In spite of their complacency, the Romans obviously observed the Gallic army closely, noting areas in which they excelled, weapons and tactics which could be adapted and incorporated into the Roman way of doing things. The Romans adopted the more agile, Gallic style of combat: the unwieldy phalanx was replaced by the more versatile maniple; the pilum, or javelin, superseded the thrusting spear; close-quarter weaponry was introduced, including heavier long swords and full-body shields (the scutum) which could be interlocked to enable tighter defense in the ‘tortoise’, or testudo. Support for the infantry came in the shape of fleet-footed troops (velites) armed with slings and javelins. The concentration of the cream of the patricians (principes) in the more vulnerable and exposed first line of infantry was abolished, and younger, highly trained soldiers replaced them.

The introduction of a daily stipend around this time brought the benefit of relaxing the bond the Roman soldier had to the land. In effect, this eventually helped usher in a professional army which could fight and be garrisoned further and further from home without the need to return to farm the lands and raise money for weapons. Booty too was an increasingly important factor in the economic equation: as Rome extended its reach, so the opulent cities of the east fell under her sway and looted booty found its way back to Rome in the baggage trains of commanders.

The Gauls left Rome a poorer place militarily and economically. They also rendered her alarmingly vulnerable, which encouraged a number of conquered Italian cities to vacillate and rebel in an attempt to regain their independence. These included all the old suspects, enemies like the Etruscans, Volsci, Hernici, and Aequi. Rome, however, responded positively to this treachery by defeating them all systematically and completely until she had reasserted her dominance. Antium, the Volsci capital, was subdued in 338 BC; in 295 BC, the Samnite Wars ended when Rome vanquished a coalition of Samnites, Gauls, Etruscans, and Umbrians. Stephen Oakley has estimated that, of the 130,000 square kilometres of land in the peninsula, the ager Romanus grew from 822 sq km (0.6 per cent) in 510 BC to 1,902 sq km in 340 BC and then to 23,226 sq km (17.9 per cent) in 264 BC. This expanse of contiguous territory made it increasingly difficult for enemies to threaten Rome. Her population was around 347,300 in 338 BC, rising to 900,000 in 264 BC.