Hatha yoga also called hatha vidya is a system of yoga introduced by Yogi Swatmarama, a sage of 15th century India, and compiler of the Hatha Yoga Pradipika. In this treatise Swatmarama introduces hatha yoga as preparatory stage of physical purification that the body practices for higher meditation. The asanas and pranayama in raja yoga were what the Hindu yogis used to physically train their body for long periods of meditation.
