Necronomicon

How Lovecraft conceived the name Necronomicon is not clear—Lovecraft said that the title came to him in a dream. Although some have suggested that Lovecraft was influenced primarily by Robert W. Chambers' collection of short stories The King in Yellow, which centers on a mysterious and disturbing play in book form, Lovecraft is not believed to have read that work until 1927.
Donald R. Burleson has argued that the idea for the book was derived from Nathaniel Hawthorne, though Lovecraft himself noted that "mouldy hidden manuscripts" were one of the stock features of Gothic literature.
Lovecraft wrote that the title, as translated from the Greek language, meant "an image of the law of the dead", compounded respectively from νεκρός nekros "dead", νόμος nomos "law", and εἰκών eikon "image". Robert M. Price notes that the title has been variously translated by others as "Book of the names of the dead", "Book of the laws of the dead", "Book of dead names" and "Knower of the laws of the dead". S. T. Joshi states that Lovecraft's own etymology is "almost entirely unsound. The last portion of it is particularly erroneous, since -ikon is nothing more than a neuter adjectival suffix and has nothing to do with eikõn (image)." Joshi translates the title as "Book considering (or classifying) the dead."
Lovecraft was often asked about the veracity of the Necronomicon, and always answered that it was completely his invention. In a letter to Willis Conover, Lovecraft elaborated upon his typical answer:

Now about the "terrible and forbidden books”—I am forced to say that most of them are purely imaginary. There never was any Abdul Alhazred or Necronomicon, for I invented these names myself. Robert Bloch devised the idea of Ludvig Prinn and his De Vermis Mysteriis, while the Book of Eibon is an invention of Clark Ashton Smith's. Robert E. Howard is responsible for Friedrich von Junzt and his Unaussprechlichen Kulten.... As for seriously-written books on dark, occult, and supernatural themes—in all truth they don’t amount to much. That is why it’s more fun to invent mythical works like the Necronomicon and Book of Eibon.

Reinforcing the book's fictionalization, the name of the book's supposed author, Abdul Alhazred, is not even a grammatically correct Arabic name. "Abdul" means "the worshiper/slave of the", and standing alone it would make no sense, as Alhazred is not a surname in the Western sense, but a reference to a person's place of birth, and its English translation starts with another "the".

Although Lovecraft insisted that the book was pure invention (and other writers invented passages from the book for their own works), there are accounts of some people actually believing the Necronomicon to be a real book. Lovecraft himself sometimes received letters from fans inquiring about the Necronomicon's authenticity. Pranksters occasionally listed the Necronomicon for sale in book store newsletters or inserted phony entries for the book in library card catalogues (where it may be checked out to one 'A. Alhazred', ostensibly the book's author and original owner). The Vatican also receives requests for this book from those who believe the Vatican Library holds a copy. 
Similarly, the university library of Tromsø, Norway, lists a translated version of the Necronomicon, attributed to Petrus de Dacia and published in 1994, although the document is listed as "unavailable".
In 1973, Owlswick Press issued an edition of the Necronomicon written in an indecipherable, apparently fictional language known as "Duriac"^. This was a limited edition of 348. The book contains a brief introduction by L. Sprague de Camp.
The line between fact and fiction was further blurred in the late 1970s when a book purporting to be a translation of "the real" Necronomicon was published. This book, by the pseudonymous "Simon," had little connection to the fictional Lovecraft Mythos but instead was based on Sumerian mythology. It was later dubbed the "Simon Necronomicon". Going into trade paperback in 1980 it has never been out of print and has sold 800,000 copies by 2006 making it the most popular Necronomicon to date. Despite its contents, the book's marketing focused heavily on the Lovecraft connection and made sensational claims for the book's magical power. The blurb states it was "potentially, the most dangerous Black Book known to the Western World". Three additional volumes have since been published — The Necronomicon Spellbook, a book of pathworkings with the 50 names of Marduk; Dead Names: The Dark History of the Necronomicon, a history of the book itself and of the late 1970s New York occult scene; and The Gates Of The Necronomicon, instructions on pathworking with the Simon Necronomicon.
A hoax version of the Necronomicon, edited by George Hay, appeared in 1978 and included an introduction by the paranormal researcher and writer Colin Wilson. David Langford described how the book was prepared from a computer analysis of a discovered "cipher text" by Dr. John Dee. The resulting "translation" was in fact written by occultist Robert Turner, but it was far truer to the Lovecraftian version than the Simon text and even incorporated quotations from Lovecraft's stories in its passages. Wilson also wrote a story, "The Return of the Lloigor", in which the Voynich manuscript turns out to be a copy of the Necronomicon.
With the success of the Simon Necronomicon the controversy surrounding the actual existence of the Necronomicon was such that a detailed book, The Necronomicon Files, was published in 1998 attempting to prove once and for all the book was pure fiction. It covered the well-known Necronomicons in depth, especially the Simon one, along with a number of more obscure ones. It was reprinted and expanded in 2003.
In 2004, Necronomicon: The Wanderings of Alhazred, by Canadian occultist Donald Tyson, was published by Llewellyn Worldwide. The Tyson Necronomicon is generally thought to be closer to Lovecraft's vision than other published versions. Donald Tyson has clearly stated that the Necronomicon is fictional, but that has not prevented his book from being the center of some controversy. Tyson has since published Alhazred, a novelization of the life of the Necronomicon's author.
Kenneth Grant, the British occultist, disciple of Aleister Crowley, and head of the Typhonian Ordo Templi Orientis, suggested in his book The Magical Revival (1972) that there was an unconscious connection between Crowley and Lovecraft. He thought they both drew on the same occult forces; Crowley via his magic and Lovecraft through the dreams which inspired his stories and the Necronomicon. Grant claimed that the Necronomicon existed as an astral book as part of the Akashic records and could be accessed through ritual magic or in dreams. Grant's ideas on Lovecraft were featured heavily in the introduction to the Simon Necronomicon and also have been backed by Tyson.