Aleister Crowley was a fairly well-known occultist. He is said to have had connections with Theosophists, Ordo Templi Orientis, as well as with the founder of Scientology, L. Ron Hubbard. Crowley is also said to have made an impression on various celebrities, such as The Beatles and also Jimmy Page of Led Zeppelin. Jimmy Page reportedly bought Crowley's former home.
Crowley wrote The Book of Law, supposedly channeled from Horus through his wife during a stay in Egypt. This book is central to the teachings of Thelema, which he also founded. It is said Aleister Crowley met a being called Lam, which from Crowley's drawing is described as resembling The Greys.