The Patanjali Yoga Sutras was written by sage Patanjali. He is believed to have lived between 500 and 200 BC. Life of sage Patanjali is obscure and there are no credible manuscripts about his life, he is known to have authored many Sanskrit works including Sanskrit grammar and works on Ayurveda. Nobody is certain whether other notable works authored by Patanjali, is the same sage who authored Patanjali Yoga Sutras, because there were many sages with the same name. He is considered to be an incarnation of Ananta, the thousand headed ruler of the serpent race, on which God Vishnu rests along with his wife Goddess Lakshmi.