Before this battle, Senones, a Gaul’s tribe, traversed Apennines in search of a new land where it could settle. Eventually, the tribe camped at a place outside Clusium town, in the Etruria valley, where it started negotiations for its rights to land ownership. This created a feeling of being threatened in the Clusians necessitating the need to seek assistance from Rome. Recently, Rome had exerted its military influence on Etruria. Due to its involvement in the recent wars, Rome sent its delegation which comprised of three ambassadors. These were to negotiate the situation.
However, the negotiations did not succeed and an army was sent by the Clusians to drive Senones out of the land. This was the point where Livy, a Roman historian, stated that the ambassadors of Rome had broken the nations’ law and took arms against Senones. A Gallic leader was killed by a Roman ambassador, Quintus Fabius. On realizing this, Senones sent for Fabius from Rome so that he could meet justice for his action. Many Romans, especially the priests, agreed that the nations’ law had been breached. However, they were mocked by Roman masses and instead, those who deserved punishment were appointed to consular power’s positions. The Gallic envoys were rightly and naturally indignant. This prompted the Senones to march to Rome from Clusium in a revenge mission.
The Gauls marched to Rome without causing harm to the people on their way. This was contrary to the expectations of most people. They passed close to cities shouting out clearly that they were headed for Rome. They also stated that they had declared a war on Romans only. They added that they considered other people as their friends. The battlefield was at approximately 18 km to the north of the city. At that time, Rome had a relatively smaller army and it’s intended to attack Gauls on the flanks that extended from a small hill where there was a Roman reserve.
On seeing the Romans occupy the hill, Brennus, the Gauls leader, assumed that their intention was to hide part of their army in order to attack them in the flanks. To ensure that this did not happen, he ordered his army to attack the reserves of the Romans instead of the main line. While advancing to attack the Roman’s reserves, panic spread among the Roman army and the left wing run away towards the Veii city which had been captured. This city was more fortified than Rome. The right wing on the other hand fled towards Rome to take refuge in a Citadel. This left the Roman walls undefended. After some days of the battle, the entire city had been looted after its occupation by the Gauls. The citadel was held out till the pay off of the Gauls.
The Romans suffered losses, but they were not huge because some of their troops escaped to Veii while others run to Rome. The Gauls threat became an apparent nightmare for the Romans until the Caesar’s Gallic War. Nevertheless, the Romans’ defeat by the Gauls marked the last time that Rome city was captured by forces that were not Roman.