Fulcanelli was likely a Frenchman educated in the ways of alchemical lore, architecture, art, science, and languages.
Theories about Fulcanelli speculate that he was one or another famous French occultist of the time: perhaps a member of the former Royal Family (the Valois), or another member of the Frères d'Heliopolis (Brotherhood of Heliopolis, a society centred around Fulcanelli which included Eugène Canseliet, Jean-Julien Champagne and Jules Boucher).