"Sacrifice is offered to her annually in the house of the consul by his wife or his mother" - the Festival of the Bona Dea in Ancient Rome

4 December in Ancient Rome, the annual secret ceremonies in honour of the Bona Dea were held in the house of a Roman principal, led by his wife, usually in their home on the Palatine Hill.
“They then escorted him to the house of a friend and neighbour, since his own was occupied by the women, who were celebrating mysterious rites to a goddess whom the Romans call Bona Dea, and the Greeks, Gynaeceia. Sacrifice is offered to her annually in the house of the consul by his wife or his mother, in the presence of the Vestal Virgins.“ (Plutarch, “Life of Cicero”)

A relief of Bona Dea on Augustus' "Ara Pacis" in Rome


With even two goddesses present in their triad of supreme deities, Roman mythology derived significantly from many other Indo-European panthea, usually dominated by three patriarchal gods. The role women themselves played in Roman religion was significantly smaller though, but almost omnipresent. Male priests might have had the lead in most offices and functions, but the order of the Vestal Virgins alone was a rarity in the Mediterranean world and their role of furthering scholarship as well as taking care of the correct observance of nearly all religious rituals, deemed necessary for the very survival of Rome itself, can hardly be underestimated – and even before cults of the Egypt and the Middle East put down roots in Imperial Rome, there were other festivals reserved for women only, such as the rites of the Bona Dea.



The Capitoline Triad - Jupiter flanked by Minerva and Juno


The true name of Bona Dea, the good goddess, was kept a secret by her priestesses, but she probably grew out of a few Ancient Italic deities, superposed by fertility goddesses of Magna Grecia. Her provenience was, besides fertility, healing, chastity and the protection of the state, and her cult is present in Rome since the days of the Middle Republic, around the 3rd century BCE, when her temple was built on the Aventine, the traditional quarter of the Roman plebs, giving her worship a certain democratic streak – up to a point that the Roman pontificate did not acknowledge an additional sanctuary for Bona Dea established by the Vestal Virgin Licina to stop the spread of her worship among the slaves of Rome. Her actual high festivals were a decidedly upper class affair, though. On December 4th, the wife of one of the Roman magistrates would host the traditional ritual acts in her home, the place would be cleansed of everything male, decorate with flowery things and vine leaves and the cultic image of the goddess would be carried by the Vestal Virgins from the Aventine to the Palatine Hill and the home of the dignitary where she would lie on a couch and take part in the secret festival that allegedly involved wine, song and dance and males were strictly off-limits.




Dressed-up Publius Clodius Pulcher during the "Bona Dea Scandal" of 62 BCE




The festival of Bona Dea went down in political history, when the rowdy Publius Clodius Pulcher tried to party crash the festival in the year of 62 BCE disguised as a woman, allegedly to seduce this year’s hostess, Caesar’s wife Pompeia, an event that led to the divorce of Caesar and a lifelong enmity between Cicero and Clodius, who escaped the following trial and verdict by bribing the jury. The scandal had a disreputable effect on the cult of the Bona Dea for decades until Clodius’ kinswoman Livia, wife of Augustus, restored the rites that continued well into the 3rd century CE, when the Bona Dea was slowly merged into that of other mother goddesses. Her temple on the Aventine remained a centre of the Roman art of healing, with its garden where tame snakes crawled about and medicinal herbs were grown by the priestesses, until the church of Santa Balbina was build on its foundations, late in the 4th century.


And more on:

http://en.wikipedia.org/wiki/Bona_Dea