Among the many books he has written we may find information on Alchemy, Qabalism, Ceremonial magic, Freemasonic Symbolism and the Western Esoteric Tradition.
His work has had strong influence upon the likes of Aleister Crowley, Madame Blavatsky and others.
Although his 'History of Magic' touches upon many famous (and infamous) magicians throughout history, Dr. John Dee (Queen Elizabeth's Conjuror) is remarkably absent.