In the section of Livy Book XXXIX preceding the one quoted below, the historian says the Bacchanalia spread from the area of the Etruscans to Rome. Earlier, the Bacchanalia had migrated from Greece to southern Italy (magna Graecia/megale Hellas).
To their religious performances were added the pleasures of wine and feasting, to allure a greater number of proselytes. When wine, lascivious discourse, night, and the intercourse of the sexes had extinguished every sentiment of modesty, then debaucheries of every kind began to be practiced, as every person found at hand that sort of enjoyment to which he was disposed by the passion predominant in his nature. Nor were they confined to one species of vice -- the promiscuous intercourse of free-born men and women; but from this store-house of villainy proceeded false witnesses, counterfeit seals, false evidences, and pretended discoveries. From the same place, too, proceeded poison and secret murders, so that in some cases, not even the bodies could be found for burial. Many of their audacious deeds were brought about by treachery, but most of them by force; it served to conceal the violence, that, on account of the loud shouting, and the noise of drums and cymbals, none of the cries uttered by the persons suffering violence or murder could be heard abroad.