The Cult of Herodias, in medieval folklore, was a coven of witches worshipping the Roman goddess Diana and the Biblical character Herodias. Fables of this cult began to spread sometime before the 10th century, were denounced by the Catholic Church as superstition or diabolical deception, and had largely died out by the time of the Reformation. The stories were picked up again in the early 20th century by some groups of modern neo-pagans, who added elements not found in the original folktales.
After the emperor Constantine had converted to Christianity and established it as the state religion of the Roman Empire, and after Theodosius had outlawed worship of the pagan gods, not all people accepted Christianity. Though classical paganism had largely disappeared from the Roman Empire by the time of Justinian, stories about pagan cults persisted into the Middle Ages.
After Christianity had forbidden non-heterosexual practices and orgies formerly common among Romans, a rumor arose that a group of women in Italy had started a cult centred on the goddess Diana. This cult, according to the story, was mainly intended for women, preferably lesbian, as many considered Diana a lesbian goddess. Some version of the tale added an explicitly anti-Christian character: Herodias, the Jewish princess who asked for the death of John the Baptist, who was deified. (Other versions of the story identify Diana's daughter, not as Herodias, but as the Germanic goddess Huldra.)
The virgin goddess became Herodias' (or Huldra's) mother. In early times, so people believed, this cult had as its deity Diana. The church was already aware of the stories about this supposed cult; in the 10th century a fragment of text called the Canon Episcopi (attributed to an otherwise-unknown Council of Anquira) made mention of it as "a perversion of the mind originated by Satan", and consider the fable of the flying women accompanied by Diana to be a "fantasy experienced while dreaming". By the 12th century the folktales about this cult had expanded to other places in Europe; the Catholic church continued to consider it delusory, attributing the stories of its existence either to demonic trickery or to folk superstition.
Jean de Salisbury, bishop of Chartres, France, made a comment on these fables in his book Policraticus, naming the goddess Herodias and Noctiluca, queen of the night (12th century). He mentioned the supposed participation of women and men in these meetings. He too considered the existence of this cult to be a fable at best.
Among some modern Wiccans, Herodias is called Aradia, a corruption of the original name, due principally to the fact that in Late Latin and Italian the "h" is mute. This name can be traced to the publication of C.G. Leland's book Aradia or The Gospel of the Witches in 1890.
See also Neopagan views of homosexuality, skyclad, Wicca.