Chakras are rotating psychic centers of consciousness. They were mentioned by Indian authors of the Yoga Upanishads as early as ca. 600 BC. Around 317/318 AD Daoist scholar Ge Hong wrote a book “Baopuzi” and there he discussed mantras and gestures for different chakras and body parts. However the classical model of 7 or 8 (7+ Bindu) main chakras from Muladhara to Sahasrara was revealed in 8th or 9th century tantric and Buddhist texts and this system prevailed. In the second half of the 20th century focus of spiritual research of chakras has slowly turned toward the trans-personal and sub-personal chakras.