Aleister Crowley was an English occultist, magician, poet, painter, novelist, and mountaineer. He was the prophet for the religion of Thelema, which he also founded. Crowley was born in 1875 into a wealthy family and attended Trinity College at Cambridge. He traveled the world widely; Egypt, America, Mexico, Australia, France, and many more countries.
Notably, in WWI he spent the war in the U.S. advocating for the Germans with his writing prowess. Later on, he revealed he did this to infiltrate and undermine German efforts in support of British Intelligence.
Crowley wrote almost his entire life on various topics. He advocated and attempted to spread the religion of Thelema until his death in 1947. Crowley is still considered a prophet in Thelema and a huge figure in the occult society today.