Original title Al Azif -- azif being the word used by Arabs to designate that nocturnal sound (made by insects) suppos'd to be the howling of daemons.
Composed by Abdul Alhazred, a mad poet of Sanaá, in Yemen, who is said to have flourished during the period of the Ommiade caliphs, circa 700 A.D. He visited the ruins of Babylon and the subterranean secrets of Memphis and spent ten years alone in the great southern desert of Arabia -- the Roba el Khaliyeh or "Empty Space" of the ancients -- and "Dahna" or "Crimson" desert of the modern Arabs, which is held to be inhabited by protective evil spirits and monsters of death. Of this desert many strange and unbelievable marvels are told by those who pretend to have penetrated it. In his last years Alhazred dwelt in Damascus, where the Necronomicon (Al Azif) was written, and of his final death or disappearance (738 A.D.) many terrible and conflicting things are told. He is said by Ebn Khallikan (12th cent. biographer) to have been seized by an invisible monster in broad daylight and devoured horribly before a large number of fright-frozen witnesses. Of his madness many things are told. He claimed to have seen fabulous Irem, or City of Pillars, and to have found beneath the ruins of a certain nameless desert town the shocking annals and secrets of a race older than mankind. He was only an indifferent Moslem, worshipping unknown entities whom he called Yog-Sothoth and Cthulhu.
In A.D. 950 the Azif, which had gained a considerable tho' surreptitious circulation amongst the philosophers of the age, was secretly translated into Greek by Theodorus Philetas of Constantinople under the title Necronomicon. For a century it impelled certain experimenters to terrible attempts, when it was suppressed and burnt by the patriarch Michael. After this it is only heard of furtively, but (1228) Olaus Wormius made a Latin translation later in the Middle Ages, and the Latin text was printed twice -- once in the fifteenth century in black-letter (evidently in Germany) and once in the seventeenth (prob. Spanish) -- both editions being without identifying marks, and located as to time and place by internal typographical evidence only. The work both Latin and Greek was banned by Pope Gregory IX in 1232, shortly after its Latin translation, which called attention to it. The Arabic original was lost as early as Wormius' time, as indicated by his prefatory note; and no sight of the Greek copy -- which was printed in Italy between 1500 and 1550 -- has been reported since the burning of a certain Salem man's library in 1692. An English translation made by Dr. Dee was never printed, and exists only in fragments recovered from the original manuscript. Of the Latin texts now existing one (15th cent.) is known to be in the British Museum under lock and key, while another (17th cent.) is in the Bibliothèque Nationale at Paris. A seventeenth-century edition is in the Widener Library at Harvard, and in the library of Miskatonic University at Arkham. Also in the library of the University of Buenos Ayres. Numerous other copies probably exist in secret, and a fifteenth-century one is persistently rumoured to form part of the collection of a celebrated American millionaire. A still vaguer rumour credits the preservation of a sixteenth-century Greek text in the Salem family of Pickman; but if it was so preserved, it vanished with the artist R. U. Pickman, who disappeared early in 1926. The book is rigidly suppressed by the authorities of most countries, and by all branches of organised ecclesiasticism. Reading leads to terrible consequences. It was from rumours of this book (of which relatively few of the general public know) that R. W. Chambers is said to have derived the idea of his early novel The King in Yellow.
This should be supplemented with a letter written to Clark Ashton Smith on November 27, 1927:
I have had no chance to produce new material this autumn, but have been classifying notes & synopses in preparation for some monstrous tales later on. In particular I have drawn up some data on the celebrated & unmentionable Necronomicon of the mad Arab Abdul Alhazred! It seems that this shocking blasphemy was produced by a native of Sanaá, in Yemen, who flourished about 700 A.D. & made many mysterious pilgrimages to Babylon's ruins, Memphis's catacombs, & the devil-haunted & untrodden wastes of the great southern deserts of Arabia -- the Roba el Khaliyeh, where he claimed to have found records of things older than mankind, & to have learnt the worship of Yog-Sothoth & Cthulhu. The book was a product of Abdul's old age, which was spent in Damascus, & the original title was Al Azif -- azif (cf. Henley's notes to Vathek) being the name applied to those strange night noises (of insects) which the Arabs attribute to the howling of daemons. Alhazred died -- or disappeared -- under terrible circumstances in the year 738. In 950 Al Azif was translated into Greek by the Byzantine Theodorus Philetas under the title Necronomicon, & a century later it was burnt at the order of Michael, Patriarch of Constantinople. It was translated into Latin by Olaus in 1228, but placed on the Index Expurgatorius by Pope Gregory IX in 1232. The original Arabic was lost before Olaus' time, & the last known Greek copy perished in Salem in 1692. The work was printed in the 15th, 16th, & 17th centuries, but few copies are extant. Wherever existing, it is carefully guarded for the sake of the world's welfare & sanity. Once a man read through the copy in the library of Miskatonic University at Arkham -- read it through & fled wild-eyed into the hills... but that is another story!
In yet another letter (to James Blish and William Miller, 1936), Lovecraft says:
You are fortunate in securing copies of the hellish and abhorred Necronomicon. Are they the Latin texts printed in Germany in the fifteenth century, or the Greek version printed in Italy in 1567, or the Spanish translation of 1623? Or do these copies represent different texts?