Name at birth: Edward Alexander Crowley
Aleister Crowley is the rule-breaking mystic whose many philosophical and occult writings form the backbone of the contemporary movement called "magick." Aleister Crowley was raised in a strict Christian family, but discovered the occult while an undergraduate at Cambridge. Combining eastern mysticism with western science, he came up with a religious system called The Law of Thelema. Referring to himself as "The Great Beast" (and allegedly, "the wickedest man alive") earned him a few disciples, but the rumors of drugs, orgies and magic ceremonies didn't make him too popular among the straight set. He outlined his ideas on Thelema in The Book of the Law (1904), and also wrote the handbook Magick (Book 4), the most famous section of which is Part III, "Magick in Theory and Practice."