The Gauls at this time were besieging Clusium, a Tuscan city. The Clusinians sent to the Romans for succour, desiring them to interpose with the barbarians by letters and ambassadors. There were sent three of the family of the Fabii, persons of high rank and distinction in the city. The Gauls received them courteously, from respect to the name of Rome, and, giving over the assault which was then ****** upon the walls, came to conference with them; when the ambassadors asking what injury they had received of the Clusinians that they thus invaded their city, Brennus, King of the Gauls, laughed and made answer: "The Clusinians do us injury, in that, being able only to till a small parcel of ground, they must needs possess a great territory, and will not yield any part to us who are strangers, many in number, and poor. In the same nature, O Romans, formerly the Albans, Fidenates, and Ardeates, and now lately the Veientines and Capenates, and many of the Faliscans and Volscians, did you injury;upon whom ye make war if they do not yield you part of what they possess, make slaves of them, waste and spoil their country, and ruin their cities; neither in so doing are cruel or unjust, but follow that most ancient of all laws, which gives the possessions of the feeble to the strong; which begins with God and ends in the beasts;since all these, by nature, seek the stronger to have advantage over the weaker. Cease, therefore, to pity the Clusinians whom we besiege, lest ye teach the Gauls to be kind and compassionate to those that are oppressed by you." By this answer the Romans, perceiving that Brennus was not to be treated with, went into Clusium, and encouraged and stirred up the inhabitants to make a sally with them upon the barbarians, which they did either to try their strength or to show their own. The sally being made, and the fight growing hot about the walls, one of the Fabii, Quintus Ambustus, being well mounted, and setting spurs to his horse, made full against a Gaul, a man of huge bulk and stature, whom he saw riding out at a distance from the rest. At the first he was not recognized, through the quickness of the conflict and the glittering of his armour, that precluded any view of him; but when he had overthrown the Gaul, and was going to gather the spoils, Brennus knew him; and, invoking the gods to be witness, that, contrary to the known and common law of nations, which is holily observed by all mankind, he who had come as an ambassador had now engaged in hostility against him, he drew off his men, and bidding Clusium farewell, led his army directly to Rome. But not wishing that it should look as if they took advantage of that injury, and were ready to embrace any occasion of quarrel, he sent a herald to demand the man in punishment, and in the meantime marched leisurely on.
The senate being met at Rome, among many others that spoke against the Fabii, the priests called fecials were the most decided, who, on the religious ground, urged the senate that they should lay the whole guilt and penalty of the fact upon him that committed it, and so exonerate the rest. These fecials Numa Pompilius, the mildest and justest of kings, constituted guardians of peace, and the judges and determiners of all causes by which war may justifiably be made. The senate referring the whole matter to the people, and the priests there, as well as in the senate, pleading against Fabius, the multitude, however, so little regarded their authority, that in scorn and contempt of it they chose Fabius and the rest of his brothers military tribunes. The Gauls, on hearing this, in great rage threw aside every delay, and hastened on with all the speed they could make. The places through which they marched, terrified with their numbers and the splendour of their preparations for war, and in alarm at their violence and fierceness, began to give up their territories as already lost, with little doubt but their cities would quickly follow; contrary, however, to expectation, they did no injury as they passed, nor took anything from the fields; and, as they went by any city, cried out that they were going to Rome; that the Romans only were their enemies, and that they took all others for their friends.
Whilst the barbarians were thus hastening with all speed, the military tribunes brought the Romans into the field to be ready to engage them, being not inferior to the Gauls in number (for they were no less than forty thousand foot), but most of them raw soldiers, and such as had never handled a weapon before. Besides, they had wholly neglected all religious usages, had not obtained favourable sacrifices, nor made inquiries of the prophets, natural in danger and before battle. No less did the multitude commanders distract and confound their proceedings; frequently before, upon less occasions, they had chosen a single leader, with the title of dictator, being sensible of what great importance it is in critical times to have the soldiers united under one general with the entire and absolute control placed in his hands. Add to all, the remembrance of Camillus's treatment, which made it now seem a dangerous thing for officers to command without humouring their soldiers. In this condition they left the city, and encamped by the river Allia, about ten miles from Rome; and not far from the place where it falls into the Tiber; and here the Gauls came upon them, and, after a disgraceful resistance, devoid of order and discipline, they were miserably defeated. The left wing was immediately driven into the river, and there destroyed; the right had less damage by declining the shock, and from the low grounds getting to the tops of the hills, from whence most of them afterwards dropped into the city; the rest, as many as escaped, the enemy being weary of the slaughter, stole by night to Veii, giving up Rome and all that was in it for lost.