Pease note: this is a different author from Alice Bailey.

Alice A. Bailey (1880-1949) was an English esoteric practitioner and writer.
At the age of 35, she entered the Theosophical Society center in Los Angeles (USA), at the Pacific Grove Theosophical Lodge. In 1919, Bailey (39 years old) severed her ties to the Theosophical Society and began to write texts that he claimed were dictated telepathically by a certain "Tibetan," or "D. K. ». She published those texts under the title Human and Solar Initiation. There she made known the existence of the spiritual hierarchy, which Madame Blavatsky had already spread, although not in an orderly way.
She later revealed that the Tibetan D.K. was the master Djwal Khul. She wrote using the teacher's name for 30 years, from 1919 until her death in 1949.