Liber AL vel Legis (), commonly known as The Book of the Law, is the central sacred text of Thelema. The book is often referred to simply as Liber AL, Liber Legis or just AL, though technically the latter two refer only to the manuscript.

The English occultist Aleister Crowley wrote the Liber AL vel Legis in 1904, saying that the book was dictated to him by a beyond-human being, Aiwass, who he later referred to as his own Holy Guardian Angel. Crowley claimed this event marked the arrival of a new stage in the spiritual evolution of humanity, to be known as the "Æon of Horus". The primary precept of this new aeon is the charge, "Do what thou wilt shall be the whole of the Law."

The book contains three chapters, each of which Crowley said had been dictated and written down in one hour, beginning at noon, on 8 April, 9 April, and 10 April in Cairo, Egypt, in the year 1904. The three chapters of the book are attributed to the deities Nuit, Hadit, and Ra-Hoor-Khuit. Rose Edith Kelly, Crowley's wife, corrected two phrases in the manuscript.

Crowley later wrote that "Certain very serious questions have arisen with regard to the method by which this Book was obtained. I do not refer to those doubts—real or pretended—which hostility engenders, for all such are dispelled by study of the text; no forger could have prepared so complex a set of numerical and literal puzzles[...]" Biographer Lawrence Sutin quotes private diaries that fit this story and writes that "If ever Crowley uttered the truth of his relation to the Book," his public account accurately describes what he remembered on this point.

Structure and title The technical title of the book is Liber AL vel Legis, sub figura CCXX, as delivered by XCIII=418 to DCLXVI, although this title never occurs in the Book itself, which refers to itself as "the Book of the Law" and "the threefold Book of Law" (chapters 1:35, 3:75). CCXX is 220 in Roman figures, representing The Tree of Life (10 numbers times 22 paths), and is the number of verses of the Book in typescript. XCIII is 93, the enumeration of both "The word of the law" Thelema and Aiwass. DCLXVI is 666, the number of Crowley as Great Beast both as Adept and Magus. This is a way of saying that the book was delivered by Aiwass (whose number is both 93 and 418) to Crowley, who is The Beast 666.

The facsimile manuscript of the Book is not, however, numbered 220, but XXXI (31) as the first chapter's verses are unnumbered in the original manuscript: that is, no verse numbers were dictated to Crowley for chapter one. Both editions were titled by Crowley AL, pronounced "El", value 31, so therefore Liber 31 is the manuscript of The Book of the Law called AL (not be confused with Liber 31 by C. S. Jones (Frater Achad), which is an exegesis of some of the qabalistic symbolism of the Book), whereas Liber 220 is the edited (strictly according to the editing instructions dictated as part of the text of the Book itself), printed form of the text.

The original title of the book was Liber L vel Legis. Crowley retitled it Liber AL vel Legis in 1921, when he also gave the handwritten manuscript its own title.Hymenaeus Beta in

Creation Summons

According to Crowley, the story began on 16 March 1904, when he tried to "shew the Sylphs" by use of the Bornless Ritual to his wife, Rose Edith Kelly, while spending the night in the King's Chamber of the Great Pyramid of Giza. Although she could see nothing, she did seem to enter into a light trance and repeatedly said, "They're waiting for you!" Since Rose had no interest in magic or mysticism, she took little interest. However, on the 18th, after he invoked Thoth (the god of knowledge), she mentioned Horus by name as the one waiting for him. Crowley, still skeptical, asked her numerous questions about Horus, which she answered accurately supposedly without having any prior study of the subject.

Crowley also gives a different chronology, in which an invocation of Horus preceded the questioning. Lawrence Sutin says this ritual described Horus in detail, and could have given Rose the answers to her husband's questions.

As part of his 'test' for Rose, Crowley wrote that they visited the Bulaq Museum where Crowley asked her to point out an image of Horus. Much to Crowley's initial amusement, she passed by several common images of the god, and went upstairs. From across the room Rose identified Horus on the stele of Ankh-ef-en-Khonsu, then housed under inventory number 666 (since moved to the Egyptian Museum of Cairo, number A 9422). The stela would subsequently be known to Thelemites (adherents of Thelema) as the "Stele of Revealing".

On 20 March, Crowley invoked Horus, "with great success". Between 23 March and 8 April, Crowley had the hieroglyphs on the stele translated. Also, Rose revealed that her "informant" was not Horus himself, but his messenger, Aiwass.

Finally, on 7 April, Rose gave Crowley his instructions—for three days he was to enter the "temple" and write down what he heard between noon and 1:00 P.M.

Speakers Although the messenger of Liber AL was Aiwass, each chapter is presented as an expression of one of three god-forms: Nuit, Hadit, and Ra-Hoor-Khuit.

The first chapter is spoken by Nuit, the Egyptian goddess of the night sky, called the Queen of Space. Crowley calls her the "Lady of the Starry Heaven, who is also Matter in its deepest metaphysical sense, who is the infinite in whom all we live and move and have our being."

The second chapter is spoken by Hadit, who refers to himself as the "complement of Nu, my bride." As such, he is the infinitely condensed point, the center of her infinite circumference. Crowley says of him, "He is eternal energy, the Infinite Motion of Things, the central core of all being. The manifested Universe comes from the marriage of Nuit and Hadit; without this could no thing be. This eternal, this perpetual marriage-feast is then the nature of things themselves; and therefore, everything that exists is a "crystallisation of divine ecstasy", and "He sees the expansion and the development of the soul through joy."

The third chapter is spoken by Ra-Hoor-Khuit, "a god of War and of Vengeance", also identified as Hoor-paar-kraat, the Crowned and Conquering Child.

Crowley sums up the speakers of the three chapters thus, "we have Nuit, Space, Hadit, the point of view; these experience congress, and so produce Heru-Ra-Ha, who combines the ideas of Ra-Hoor-Khuit and Hoor-paar-kraat."

The book also introduces:

The Beast (The Great Beast 666, TO MEGA THERION, Aleister Crowley) The Scarlet Woman, also known as Babalon, the Mother of Abominations Ankh-af-na-khonsu (the historical priest associated with the Stele of Revealing)

Writing Crowley said he wrote The Book of the Law on 8, 9 and 10 April 1904, between the hours of noon and 1:00 pm, in the flat where he and his new wife were staying for their honeymoon, which he described as being near the Boulak Museum in a fashionable European quarter of Cairo, let by the firm Congdon & Co. The apartment was on the ground floor, and the "temple" was the drawing room.

Crowley described the encounter in detail in The Equinox of the Gods, saying that as he sat at his desk in Cairo, the voice of Aiwass came from over his left shoulder in the furthest corner of the room. This voice is described as passionate and hurried, and was "of deep timbre, musical and expressive, its tones solemn, voluptuous, tender, fierce or aught else as suited the moods of the message. Not bass—perhaps a rich tenor or baritone." Further, the voice was devoid of "native or foreign accent".

Crowley also got a "strong impression" of the speaker's general appearance. Aiwass had a body composed of "fine matter", which had a gauze-like transparency. Further, he "seemed to be a tall, dark man in his thirties, well-knit, active and strong, with the face of a savage king, and eyes veiled lest their gaze should destroy what they saw. The dress was not Arab; it suggested Assyria or Persia, but very vaguely.

Despite initially writing that it was an "excellent example of automatic writing", Crowley later insisted that it was not just automatic writing (though the writing included aspects of this, since when Crowley tried to stop writing he was compelled to continue. The writing also recorded Crowley's own thoughts). Rather he said that the experience was exactly like an actual voice speaking to him. This resulted in him disclaiming authorship of the work in the usual sense:

Note, moreover, with what greedy vanity I claim authorship even of all the other A∴A∴ Books in Class A, though I wrote them inspired beyond all I know to be I. Yet in these Books did Aleister Crowley, the master of English both in prose and in verse, partake insofar as he was That. Compare those Books with The Book of the Law! The style [of the former] is simple and sublime; the imagery is gorgeous and faultless; the rhythm is subtle and intoxicating; the theme is interpreted in faultless symphony. There are no errors of grammar, no infelicities of phrase. Each Book is perfect in its kind.

I, daring to snatch credit for these [...] dared nowise to lay claim to have touched The Book of the Law, not with my littlest finger-tip.

Crowley himself was initially opposed to the book and its message. Shortly after making a few copies for evaluation by close friends, the manuscript was misplaced and forgotten about. It would be several years before it was found, and the first official publication occurred in 1909.

Original manuscript A facsimile of the original handwritten manuscript was published in The Equinox, Volume I, Number VII, in 1912. In 1921, Crowley gave the manuscript its own title, "AL (Liber Legis), The Book of the Law, sub figura XXXI", to distinguish it from the typeset version. It is now sometimes referred to as simply "Liber XXXI".

The original manuscript was sent on Crowley's death to Karl Germer, the executor of his will and head of Ordo Templi Orientis (O.T.O.). On Germer's death no trace of it could be found in his papers. There matters rested until 1984, when Tom Whitmore, the new owner of a house in Berkeley, California, began searching through the junk left in the basement by the previous owner. Among the used mattresses, lumber, and outdated high school textbooks were two boxes of assorted papers and newspaper clippings dealing with Germer's affairs, the charter of the O.T.O. and an envelope containing the manuscript of The Book of the Law. Whitmore donated the papers to the O.T.O.

Changes to the manuscript The final version of Liber Legis includes text that did not appear in the original writing, including many small changes to spelling. In several cases, stanzas from the Stele of Revealing were inserted within the text.

The Comment Based on several passages, including: "My scribe Ankh-af-na-khonsu, the priest of the princes, shall not in one letter change this book; but lest there be folly, he shall comment thereupon by the wisdom of Ra-Hoor-Khuit" (AL I:36), Crowley felt compelled to interpret AL in writing. He wrote two large sets of commentaries where he attempted to decipher each line.

In 1912, he prepared AL and his current comments on it for publication in The Equinox, I(7). However, he was not satisfied with this initial attempt. He recalls in his confessions () that he thought the existing commentary was "shamefully meagre and incomplete." He later explains, "I had stupidly supposed this Comment to be a scholarly exposition of the Book, an elucidation of its obscurities and a demonstration of its praeterhuman origin. I understand at last that this idea is nonsense. The Comment must be an interpretation of the Book intelligible to the simplest minds, and as practical as the Ten Commandments." Moreover, this Comment should be arrived at "inspirationally", as the Book itself had been.