The mythical figure in a famous nineteenth-century occult hoax initiated by Leo Taxil, pseudonym of Gabriel Jogand-Pagés, a French journalist. From 1885 to 1886, Taxil published a sensational story that one branch of Freemasonry was following a form of devil-worship called Palladianism, of which Diana Vaughan was the High Priestess. Allegedly, she was the descendent of the seventeenth-century alchemist Thomas Vaughan.
These revelations synchronized with Roman Catholic opposition to Freemasonry (based upon their support of democratic trends in nineteenth-century Europe) and were profitable for Taxil. Diana Vaughan was supposed to have repented to her Satanist background and embraced the Catholic Church. Her memoirs were read with satisfaction by the pope himself.
An announcement appeared that she would appear at a press conference on Easter Monday 1897. Instead, Taxil appeared and calmly revealed his hoax, stating that he was merely anxious to see how far he could dupe the church. News of this deception was badly received, for the plot had lasted three or four years, and Taxil had to be smuggled away under police protection. In Britain, the hoax was exposed by occult scholar Arthur Edward Waite in his book Devil Worship in France (1896).
Waite, Arthur Edward. Devil Worship in France; or, The Question of Lucifer: A Record of Things Seen and Heard in the Secret Societies According to the Evidence of Initiates. London, George Redway, 1896.