Aleister Crowley (1875-1947), an influential English occultist, ceremonial magician, poet, painter, novelist, and mountaineer, was a pivotal figure in the early 20th-century esoteric circles and had a significant impact on modern occultism. Born Edward Alexander Crowley, he was venerated in some circles as a prophet and vilified in others as a charlatan. Crowley founded the religion of Thelema, professing that its guiding tenet was 'Do what thou wilt shall be the whole of the Law.' He saw himself as the prophet entrusted with guiding humanity into the so-called Aeon of Horus. Crowley's prolific writings include 'The Book of the Law,' which he claimed was dictated to him by a supernatural entity and became the cornerstone of Thelema. His interest in the occult led him to produce works on various mystical and magical systems, one of which is 'The Lesser Key of Solomon,' also known as 'Lemegeton,' a grimoire that, contrary to some beliefs, was not written solely by Crowley. It is actually a compilation of materials from the 17th century, which he may have edited or introduced to a broader audience. Crowley's literary style is characterized by a blend of eloquent prose and poetry, as well as the use of symbolic and allegorical references to esoteric and mystical themes. Despite controversies surrounding him, Crowley's influence on Western esotericism and countercultural movements can't be overstated, leaving a legacy that endures in the works of later occultists and in popular culture.