Allan Bennett was born in London, England December 8, 1872. Bennett was already a respected member of the Hermetic Order of the Golden Dawn when Aleister Crowley joined and soon enough began giving Crowley private tutoring. Eventually he became a Buddhist and moved to Sri Lanka (then called Ceylon) and became a monk, taking the name Bhikkhu Ananda Metteyya. At one point, Aleister joined him in Sri Lanka to pursue Buddhist studies and in fact self-identified as a Buddhist for many years, even after receiving The Book of The Law in Cairo in 1904.
According to Wikipedia:
“Bennett was, along with George Cecil Jones, Crowley’s primary teacher during his days in the Hermetic Order of the Golden Dawn. Bennett was educated atHollesly College, and scraped by as an analytical chemist. Bennett was initiated into the G.D. in 1894, taking the motto “Iehi Aour” (“let there be light”). He was always very poor and tormented by illness, but still made a strong impression on other occultists of the time.
Bennett was one of the more brilliant minds in the order, and favored mysticism and white magic; he was almost wholly concerned with enlightenment rather than siddhis (magical powers). Bennett had high regard for Golden Dawn leader S. L. Mathers, and with him began working on a book of Hermetic Qabalahcorrespondences that Crowley would later expand upon as Liber 777.
Soon after meeting, Crowley invited Bennett to come stay with him, as Bennett was living in a dilapidated shared apartment. In return, Bennett trained Crowley in the basics of magic and tried to instill a devotion to white magic. Bennett was generally ascetic and sexually chaste, a marked contrast to Crowley’s libertine attitude. Nevertheless he was an enthusiastic user of mind changing drugs (with which he treated recurrent asthma) and introduced Crowley to this aspect of his occult researches. Crowley once remarked concerning Bennett’s powers: Bennett had constructed a magical wand out of glass, which he carried with him. Crowley himself stated it to look similar in appearance to a chandelier. As it so happened, Crowley and Bennett were walking along one day and came across a group of theosophists who were ridiculing the use of wands. ‘Allan promptly produced his and blasted one of them. It took fourteen hours to restore the incredulous individual to the use of his mind and his muscles.'”
Read more here: https://en.wikipedia.org/wiki/Charles_Henry_Allan_Bennett
A collection of his writings have been posted here: http://hermetic.com/bennett/