"Hatha Yoga Pradipika is a classic Sanskrit manual on Hatha Yoga, written by Swami Swatmarama, a disciple of Swami Goraknath. Said to be the oldest surviving text on the Hatha Yoga, it is one of the three classic texts of Hatha Yoga, the other two being the Gheranda Samhita and the Shiva Samhita. The book was written in 15th century [AD]. The work is derived from older Sanskrit texts and Swami Swatamarama's own yogic experiences. Many modern English translations of the book are available. The book includes information about asanas, pranayama, chakras, kundalini, bandhas, kriyas, shakti, nadis and mudras among other topics. It runs in the line of Hindu yoga (to distinguish from Buddhist and Jain yoga) and is dedicated to Lord Adinath, a name for Lord Shiva (the Hindu god of destruction and renewal), who is alleged to have imparted the secret of Hatha Yoga to his divine consort Parvati." (Quote from wikipedia.org)