No one knows exactly when the Gauls first entered Northern Italy. Some
think that it was as long back as the time of the Tarquins, while
others put it only ten or twenty years before the battle of the Allia--
410-400 B.C.] It was they who had weakened the Etruscans and made it
possible for the Romans to capture Veii. Afterwards they came before
the city of Clusium (B.C. 391), and the people in distress begged for
aid from Rome. No help was given, but ambassadors were sent to warn the
invaders courteously not to attack the friends of the Roman people who
had done them no harm. Such a request might have had an effect upon a
nation that knew the Romans better, but the fierce Northerners who knew
nothing of courtesy replied that if the Clusians would peaceably give
up a portion of their lands, no harm should befall them; but that
otherwise they should be attacked, and that in the presence of the
Romans, who might thus take home an account of how the Gauls excelled
all other mortals in bravery. Upon being asked by what right they
proposed to take a part of the Clusian territory, Brennus, the leader
of the barbarians, replied that all things belonged to the brave, and
that their right lay in their trusty swords.

In the battle that ensued, the Roman ambassadors fought with the
Clusians, and one of them killed a Gaul of great size and stature. This
was made the basis for an onset upon Rome itself. Then the Romans must
have remembered how just before the hero of Veii had gone into
banishment, a good and respectable man reported to the military
tribunes that one night as he was going along the street near the
temple of Vesta, he heard a voice saying plainly to him: "Marcus
Cædicius, the Gauls are coming!" Probably they remembered, too, how
lightly they esteemed the information, and how even the tribunes made
sport of it. Now the Northern scourge was actually rushing down upon
them, and Camillus was gone! In great rage the invaders pushed on