The text was dictated to Crowley in Cairo, Egypt, over three days in April 1904 by a discarnate entity called Aiwass.
Aiwass, the voice he took down, is named in the text itself as the minister of Hoor-paar-kraat, and the book calls its scribe Ankh-af-na-khonsu, after the priest named on an ancient Egyptian stele that Crowley and his wife saw in a Cairo museum, later called the Stele of Revealing.