Battle of the Allia

The Battle of the Allia, fought around 390 BC near the Allia River in Italy, was a significant conflict in which the Roman Republic faced an invasion by the Gauls, led by Brennus. The Romans, caught off guard and poorly organized, suffered a decisive defeat. This battle resulted in the Gauls sacking Rome shortly afterward, a traumatic event for the city. It highlighted the vulnerabilities of early Roman military strength and spurred reforms within the Roman army, ultimately leading to Rome's rise as a dominant power in the region.