This book “Introduction to Tantra Sastra” written by Sir. John Woodroffe (1865–1936) also known by his pseudonym Arthur Avalon, was originally published as the Introduction to his English translation with notes of "Maha Nirvana Tantra (Tantra of Great Liberation)".
In this book he gives an outline of Tantra Sastra for beginners. He was a British Orientalist whose work helped to unleash in the West a deep and wide interest in Hindu philosophy and Yogic practices. He is known as the father of Tantric Studies. His works on Tantra such as "Serpent Power, Shakti and Shakta, Garlanda of letters, etc" have remained very popular even after many decades.
About the Author:
Sir John Woodroffe settled in India and was totally enchanted by the Tantra Sastra. Perhaps he was the first to bring out in English a number of Books on the subject for the benefit of English Reader. He has done immense service to the practitioners of Tantra and has authored more than a dozen Books.