To what secret society does Jacques saniere belong?

Jacques Saunière, a fictional character from Dan Brown's novel "The Da Vinci Code," is depicted as a member of the Priory of Sion, a secret society. This group is portrayed as a protector of ancient secrets related to the Holy Grail and the true nature of Mary Magdalene. The Priory of Sion, however, is a largely fictional creation, although it draws on elements of historical mystique. In reality, the society has been the subject of various conspiracy theories but lacks concrete evidence of existence prior to the 20th century.