In the 4th century BC, Rome had come under attack by the Gauls, who now extended their power in the Italian peninsula beyond the Po Valley and through Etruria. On 16 July 390 BC, a Gallic army under the leadership of tribal chieftain Brennus, met the Romans on the banks of the Allia River ten miles north of Rome. Brennus defeated the Romans, and the Gauls marched to Rome. Most Romans had fled the city, but some barricaded themselves upon the Capitoline Hill for a last stand. The Gauls looted and burned the city, then laid siege to the Capitoline Hill. The siege lasted seven months. The Gauls then agreed to give the Romans peace in exchange for of gold. According to later legend, the Roman supervising the weighing noticed that the Gauls were using false scales. The Romans then took up arms and defeated the Gauls. Their victorious general Camillus remarked "With iron, not with gold, Rome buys her freedom."