The Gauls Sack Rome

What happened

A Gallic army of the Senones under the chieftain Brennus routed the Romans at the River Allia and then sacked the city itself, which had been left largely undefended. A garrison held out on the Capitoline Hill until the Romans paid a ransom in gold for the Gauls to withdraw.

Why it matters

The traumatic sack — Rome's only fall to a foreign enemy for the next eight centuries — spurred the Romans to strengthen their walls and reform their army.

Sources

• World History Encyclopedia. The Sack of Rome by the Gauls, 390 BCE · Reputable source