The preface was written by Walter Evans-Wentz, an Oxford scholar of anthropology, a writer who was a pioneer in the study of Tibetan Buddhism and an author of The Tibetan Book of the Dead and Tibet's Great Yogi Milarepa.
Yukteswar Giri, Yogananda's guru, told him about a significant prediction made by Lahiri Mahasaya, Yukteswar's guru [REF].