When Was the Battle of Allia and What Was Its Significance?

Today, we think of the Romans as all-powerful imperialists, mythologised to the point where their leaders are seen as more like gods than human beings. But back in 390 BC, Ancient Rome was still very much a regional power, confined to the Latin-speaking central part of Italy.

On 18 July of that year, the Romans suffered one of the worst military defeats in their history, with their capital being ravaged to near total destruction. So who were the victors who brought Rome to its knees?

Here come the Gauls

To the north of Roman territory at that time lay various other Italian city-states and, beyond them, the many tribes of the warlike Gauls.

A few years earlier, the Gauls had poured over the Alps and invaded much of northern modern-day Italy, shaking up the balance of power in the region. In 390 BC, ancient chroniclers say that Aruns, a young man of the northern Etruscan city of Clusium, called upon the recent invaders to help him oust Lucumo, the King of Clusium.

Aruns alleged that the king had exploited his authority to commit the heinous act of raping his wife. However, when the Gauls besieged the city of Clusium, the inhabitants perceived a looming threat and urgently sought assistance from Rome, situated 83 miles to the south, to mediate the escalating situation.

Known as the Eternal City, ancient Rome was one of the greatest civilisations in human history, but how did it come about? In this episode Tristan is joined by Professor Guy Bradley from Cardiff University to discover more about the origins of Rome around the 8th century B.C. (TW: This episode contains reference to rape)

Listen Now

The Roman response was to send a deputation of three young men from the powerful Fabii family to Clusium to serve as neutral negotiators. Aware that the threat of the Gauls would only grow if they were allowed through the gates of the city, these ambassadors told the northern invaders that Rome would fight to defend the town if it was attacked, and demanded that the Gauls stand down.

The Gauls grudgingly accepted, but only on the condition that the Clusians grant them a generous amount of land. This outraged Lucumo’s people so much that a violent scuffle broke out and, amid the random violence, one of the Fabii brothers killed a Gallic chieftain. This act violated Rome’s neutrality and broke the primitive rules of war.

Though the fight was broken up with the brothers unscathed, the Gauls were outraged and withdrew from Clusium to plan their next move. Once the Fabiis returned to Rome, a Gaul delegation was sent to the city to demand that the brothers be handed over for justice.

Soldiers of Gaul, as imagined by a late 19th-century illustrator for the Larousse dictionary, 1898. Image credit: Public Domain, via Wikimedia Commons

However, wary of the powerful Fabii family’s influence, the Roman Senate instead voted to give the brothers’ consular honours, understandably enraging the Gauls further. A huge Gallic army then gathered in northern Italy and began a march on Rome.

According to the admittedly semi-legendary accounts of later historians, the Gauls soothed the terrified peasants they met along the way by telling them that they had eyes only for Rome and its destruction.

Almost total annihilation

According to the celebrated ancient historian Livy, the Romans were stunned by the swift and confident advance of the Gauls and their chieftain, Brennus. As a result, no special measures had been taken to raise extra forces by the time the two armies met on 18 July at the river Allia, just a few miles north of Rome.

A cunning tactician, Brennus exploited weaknesses in the thin Roman line in order to force their soldiers into flight, and went on to win a victory that surpassed even his own wildest expectations. Rome now lay defenceless.

‘Brennus and His Share of the Spoils’ by Paul Jamin (cropped). Image credit: Public domain, via Wikimedia Commons

As the Gauls advanced, the fighting men of Rome – as well as the most important senators – took refuge on the fortified Capitoline hill and prepared for a siege. This left the lower city undefended and it was razed, raped, pillaged and looted by the gleeful attackers.

Luckily for the future of Rome, however, the hill resisted all attempts at a direct assault, and Roman culture escaped complete destruction.

Gradually, plague, scorching heat and boredom frustrated those besieging the Capitoline and the Gauls agreed to go away in return for a huge sum of money, which was paid to them. Rome had just about survived, but the sacking of the city left scars on the Roman psyche – not least a strong fear and hatred of the Gauls. It also ushered in a series of military reforms that would power Rome’s expansion beyond Italy.