The life and activities of Tantric Siddhas was mysterious to the common people, so that people were either afraid or hated this path and its followers. A number of scholars had criticized this path due to its practices but so many scholars are in favour of this cult and its teachings. Now it is the time to let know the people its reality, so that I have tried my best to reveal all the mysteries of this tradition. In this book discussion was made about the origin and development of Buddhist Tantra, its divisions, literature, deities, geographical expansion of the cult, Siddha tradition and the life-sketch of eighty-four Siddhas. The book is well supported by illustrations, maps and reliable information. The author has tried his best to consult original texts of Tantra on various topics.