Blavatsky
Original sense
She knew the tantric cakras as centres in the subtle body and mentioned them in connection with kundalini and the siddhis, but she did not teach the now-standard seven rainbow centres from root to crown. She was consistently hostile to public hatha-yogic stimulation of those centres as reckless.
The ‘chakras’ in the body of the Yogî are the centres of force… not to be meddled with by the ignorant.
C. W. Leadbeater’s The Chakras (1927) fixed the Western seven-colour, seven-gland system. That book, not the Secret Doctrine, is the parent of the New Age poster. Blavatsky’s contribution was to make Indian subtle-body vocabulary thinkable in English occultism at all.