The night-time mysteries of Bacchus, the Bacchanalia, spread through Italy in the early second century BC and provoked one of the most striking acts of religious repression in Roman history. In 186 BC, the historian Livy relates, the Senate, alarmed by rumours of secret oaths, mixed nocturnal gatherings of men and women, and crimes committed under cover of the cult, moved to suppress it: initiates were hunted down, many were executed, and a decree, the senatus consultum de Bacchanalibus, survives inscribed on bronze, sharply restricting the rites and forbidding assembly without the Senate's leave.
The episode is a key document for how the Roman state, tolerant of many gods, could react with force against a cult it saw as a threat to public order and its own authority. Alongside this darker history stood the harmless public festival of Liber, the Liberalia of 17 March, a day for the vintage-god on which young men traditionally assumed the adult toga virilis.