In the early 4th century BC (391 BC according to Varronian chronology) it was besieged by Gauls, and the Clusines called upon Rome to intermediate. However, in the following negotiations, one of the Roman delegates, of the gens Fabia, killed a Gallic leader. When the Romans refused to hand over the Fabii and in fact appointed two members of the family as consuls for the next year, the enraged Gauls broke up their siege and under the leadership of Brennus they marched onto and subsequently sacked Rome.