2010 Reprint of 1903 Edition. The Book of Goetia, or the Lesser Key of Solomon the King Clavicula Salomonis]. Introductory essay by Aleister Crowley. The Lesser Key of Solomon or, Clavicula Salomonis, is an anonymous 17th-century grimoire, and one of the most popular books of demonology. It has also long been widely known as the Lemegeton. It appeared in the 17th century, but much was taken from texts of the 16th century and late-medieval grimoires. It is likely that books by Jewish kabbalists and Muslim mystics were also inspirations. Some of the material in the first section, concerning the summoning of demons, dates to the 14th century or earlier. The book claims that it was originally written by King Solomon, although this is certainly incorrect. The Lesser Key of Solomon contains detailed descriptions of spirits and the conjurations needed to invoke and oblige them to do the will of the conjurer (referred to as the "exorcist"). It details the protective signs and rituals to be performed, the actions necessary to prevent the spirits from gaining control, the preparations prior to the invocations, and instructions on how to make the necessary instruments for the execution of these rituals.