Aleister Crowley (//; born Edward Alexander Crowley; 12 October 1875 – 1 December 1947) was an English occultist, ceremonial magician, poet, painter, novelist, and mountaineer. He founded the religion and philosophy of Thelema, identifying himself as the prophet entrusted with guiding humanity into the Æon of Horus in the early 20th century.
Born to a wealthy Plymouth Brethren family in Royal Leamington Spa, Warwickshire, Crowley rejected this fundamentalist Christian faith to pursue an interest in Western esotericism. He was educated at the University of Cambridge, where he focused his attentions on mountaineering and poetry, resulting in several publications. Some biographers allege that here he was recruited into a British intelligence agency, further suggesting that he remained a spy throughout his life. In 1898 he joined the esoteric Hermetic Order of the Golden Dawn, where he was trained in ceremonial magic by Samuel Liddell MacGregor Mathers and Allan Bennett. Moving toBoleskine House by Loch Ness in Scotland, he went mountaineering in Mexico with Oscar Eckenstein, before studying Hindu and Buddhist practices in India. He married Rose Edith Kelly and in 1904 they honeymooned inCairo, Egypt, where Crowley claimed to have been contacted by a supernatural entity named Aiwass, who provided him with The Book of the Law, a sacred text that served as the basis for Thelema. Announcing the start of the Æon of Horus, The Book declared that its followers should adhere to the code of "Do what thou wilt" and seek to align themselves with their Will through the practice of magick.