The Senones, a tribe of the Gauls, led by their chief Brennus, laid siege to Clusium, the powerful Etruscan city over which Lars Porsena once reigned. Such reputation had Rome gained through her conquests in Etruria, that Clusium applied to her for aid (B.C. 391). The Senate sent three embassadors, sons of the chief pontiff, Fabius Ambustus, to warn the barbarians not to touch an ally of Rome. But the Gauls treated their message with scorn; and the embassadors, forgetting their sacred character, fought in the Clusine ranks. One of the Fabii slew with his own hands a Gallic chieftain, and was recognized while stripping off his armor. Brennus therefore sent to Rome to demand satisfaction. The Roman people not only refused to give it, but elected the three Fabii as Military Tribunes for the following year. On hearing of this insult, the Gauls broke up the siege of Clusium, and hastened southward toward Rome. All the inhabitants fled before them into the towns. They pursued their course without injuring any one, crying to the guards upon the walls of the towns they passed, "Our way lies for Rome." On the news of their approach the Roman army hurried out of the city, and on the 16th of July (B.C. 300), a day ever after regarded as disastrous, they met the Gauls on the Allia, a small river which flows into the Tiber, on its left bank, about eleven miles from Rome. Brennus attacked the Romans on the flank, and threw them into confusion. A general panic seized them: they turned and fled. Some escaped across the Tiber to Veii, and a few reached Rome, but the greater number were slain by the Gauls. The loss at the Allia had been so great that enough men were not left to guard the walls of the city. It was therefore resolved that those in the vigor of their age should withdraw to the Capitol, taking with them all the provisions in the city; that the priests and Vestal Virgins should convey the objects of religious reverence to Caere; and that the rest of the population should disperse among the neighboring towns. But the aged senators, who had been Consuls or Censors, seeing that their lives were no longer of any service to the state, sat down in the forum on their curule thrones awaiting death. When the Gauls entered the city they found it desolate and deathlike. They marched on, without seeing a human being till they came to the forum. Here they beheld the aged senators sitting immovable, like beings of another world. For some time they gazed in awe at this strange sight, till at length one of the Gauls ventured to go up to M. Papirius and stroke his white beard. The old man struck him on the head with his ivory sceptre; whereupon the barbarian slew him, and all the rest were massacred. The Gauls now began plundering the city; fires broke out in several quarters; and with the exception of a few houses on the Palatine, which the chiefs kept for their own residence, the whole city was burnt to the ground.