Barbarians at the Gate

According to legend, after the victory over the Veii, the Romans controlled the land north of the Tiber and began to populate it with their own citizens.
   -The rich Etruscan soil alleviated Rome's problem with famine.
   -Became a commercial hub in central Italy.
      -Controlled the salt trade, which brought them great wealth.
-What about the Gauls?
   -First of all, this name isn't entirely accurate.  "Gauls" is/was a term used for all the barbarian tribes who lived in and around the Alps during this time.  There was no unity among these tribes, and they fought against each other all the time.
-The Senones- the infamous Gallic tribe that sacked Rome, led by a dude named Brennus.
   -The official story is that Brennus attacked the Etruscan city of Clusium, which begged Rome for help.
      -Rome was cautious, since Clusium used to be an enemy, but soon realized that the Senones were major threat to the entire peninsula.
         -Roman envoys led Clusium's army into battle, so because Rome had gotten involved, Brennus decided to fuck up the Etruscans AND Rome.
      -Modern historians find this official version of the story unlikely, and there is evidence to suggest that Brennus had temporarily allied with Syracuse to distract Rome while Syracuse dominated Sicily and amassed their power.
         -This was especially important because the Romans were allies of a Sicilian city called Messana.
-390 BC- According to Roman records, this was when Rome was sacked.
   -The Romans gathered an army of 12,000 - 25,000 men.
   -The Senones, on the other hand, were a horde of huge, ugly, long-haired, loud, painted, crazy dudes.
      -This scared the Romans (who had probably never fought an army like this before), and many of them fled as their phalanxes were massacred.
         -The Senones moved onto Rome and found the city undefended.
            -The people had either fled the city or were hiding in its citadel.  So, while they raided the city, the Senones laid siege to the citadel, and the Romans inside began to die of disease and starvation.
               -Finally, the Romans had had enough, and paid off the Gauls to leave.  However, the story that the Gauls left and then were chased out of Italy by the Romans is probably fiction (see below).
-Anyway, Rome was now in ruins.
   -All of the historical records were destroyed.
   -Rome was severely weakened, obviously.
   -According to legend, after the exiled dictator, Marcus Furius Camillus chased off the Senones, he was able to restore morale to the Romans, and was hailed as the "Second Founder of Rome" (AKA a second Romulus).