Etruscan territory has shrunk as a direct result of challenges by the Latin League in central Italy.
Celtic tribes (“Gauls” according to Roman historian Levy and others); called Senones by Polybius), under King Brennus, had crossed the Alps in about 400, and shatter the Etruscan defenses at Clusium (Chiusi) in 391.
A call for aid brings a Roman peace delegation that attempts, vainly, to persuade the Gauls to return north, apparently offering a diplomatic insult in the process.
Refusing, …