Problem of close connection of cults. Their apparent divergence. Nature of deities examined. Attis. Mithra. The Messianic Feast. Dieterich, _Eine Mithrasliturgie_. Difference between the two initiations. Link between Phrygian, Mithraic, and Christian, Mysteries to be found in their higher, esoteric, teaching. Women not admitted to Mithraic initiation. Possible survival in Grail text. Joint diffusion through the Roman Empire. Cumont’s evidence. Traces of cult in British Isles. Possible explanation of unorthodox character of Grail legend. Evidence of survival of cult in fifth century. The _Elucidation_ a possible record of historic facts. Reason for connecting Grail with Arthurian tradition. CHAPTER XIII The Perilous Chapel The adventure of the Perilous Chapel in Grail romances. _Gawain_ form. _Perceval_ versions. _Queste. Perlesvaus. Lancelot. Chevalier à Deux Espées_. Perilous Cemetery. Earliest reference in _Chastel Orguellous. Âtre Perilleus. Prose Lancelot_. Adventure part of ‘Secret of the Grail.’ The Chapel of Saint Austin. _Histoire de Fulk Fitz-Warin_. Genuine record of an initiation. Probable locality North Britain. Site of remains of Mithra-Attis cults. Traces of Mystery tradition in Medieval romance. _Owain Miles_. Bousset, _Himmelfahrt der Seele_. Parallels with romance. Appeal to Celtic scholars. Otherworld journeys a possible survival of Mystery tradition. The Templars, were they Naassenes? CHAPTER XIV The Author _Provenance_ and authorship of Grail romantic tradition. Evidence points to Wales, probably Pembrokeshire. Earliest form contained in group of _Gawain_ poems assigned to Bleheris. Of Welsh origin. Master Blihis, Blihos, Bliheris, Bréri, Bledhericus. Probably all references to same person. Conditions of identity. Mr E. Owen, and Bledri ap Cadivor. Evidence not complete but fulfils conditions of problem Professor Singer and possible character of Bleheris’ text. Mr Alfred Nutt. Irish and Welsh parallels. Recapitulation of evolutionary process. Summary and conclusion. CHAPTER I Introductory In view of the extensive literature to which the Grail legend has already given birth it may seem that the addition of another volume to the already existing _corpus_ calls for some words of apology and explanation. When the student of the subject contemplates the countless essays and brochures, the volumes of studies and criticism, which have been devoted to this fascinating subject, the conflicting character of their aims, their hopelessly contradictory results, he, or she, may well hesitate before adding another element to such a veritable witches’ cauldron of apparently profitless study. And indeed, were I not convinced that the theory advocated in the following pages contains in itself the element that will resolve these conflicting ingredients into one harmonious compound I should hardly feel justified in offering a further contribution to the subject.