Sanatan is a Sanskrit word which means the eternal or universal laws and duties that we need to follow in order to attain union with the Divine. It is based on an approach of complete personal development (mind, body and spirit) based on the ancient teachings of Yoga.
Sanatan Yoga was founded by Yogachariya Jnandev, who follows the Gitananda tradition of Yoga.
Yogamaharishi Dr. Swami Gitananda Giri was the founder of the Gitananada Yoga tradition. He embodied the Bengali tantric tradition of his life-long guru Sri Kanakananda Swamigal with the Shiva Yoga and ritualistic expertise of the line of gurus of Sri Kambliswamy Madam, as imparted to him by his predecessor Sri Shankaragiri Swamigal. Today, the tradition is continued by his wife, Ammaji Yogacharini Meenakshi Devi Bhavanani and his son, Yogacharya Dr Ananda Balayogi Bhavanani.
One of Swami Gitananda's foremost messages was "yoga is a way of life". Meaning that it is not just the physical practice but encompasses all aspects of life which is where the eight limbs of yoga (ashtanga) comes into effect.