The Gauls at this time were besieging Clusium, a Tuscan city. The Clusinians sent to the Romans for succor, desiring them to interpose with the barbarians by letters and ambassadors. The Romans, perceiving that Brennus, the leader of the Gauls, was not to be treated with, went into Clusium and encouraged 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, who had come as an ambassador, 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 the armor, 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 witnesses 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 against Rome. Whilst the barbarians were 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 favorable sacrifices, nor made inquiries of the prophets, natural in danger and before battle. No less did the multitude of 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 solders 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 humoring their solders. 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 ground 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.