Ancient Rome: Battle of the Allia

July 18, 390 BC - Facing a much superior Gallic army, the forces of the Roman Republic are routed at the Battle of the Allia. The conflict originated following the Gallic invasion of Siena and an attack on the town of Clusium. Though not allied with Rome, the Clusians called on Rome for aid. Rather than send troops, Rome dispatched a commission to investigate the situation and negotiate with the Gauls. When discussions broke down, Quintus Fabius killed one of the Gallic leaders.

In response, the Gauls demanded Rome turn over Fabius so that he could be punished. The Romans refused and instead appointed him a military tribune. Marching on Rome with 70,000 men, the Gauls encountered six Roman legions, numbering about 40,000, near the Allia River. The Gauls, commanded by Brennus, attacked, breaking the thin Romans lines and forced them to flee towards Veii. Moving in pursuit, the Gauls were able to sack most of Rome and laid siege to the city's populace which had sought refuge on the Capitoline Hill. Not possessing the equipment for a long siege, Brennus accepted one thousand pounds of gold as ransom for the city and departed with his army.