The origin of this dossier of studies is a symposium, held in April 1984 by the Institute for the History of Religions at the University of Copenhagen, on the occasion of Professor Ugo Bianchi's visit. The intention to publish the symposium ripened during the rest of 1984, and to the original presentations were added the contribution by Per Bilde on Roman Mithraism and the editor's Attis or Osiris?.