"John Grant (born 1949) is a Scottish writer and editor of science fiction, fantasy, and non-fiction. Born as Paul le Page Barnett, Grant has sometimes written under his own name "Paul Barnett" or as "Eve Devereux". The author of some 70 books in all, he has published numerous original novels, as well as one novel in the Judge Dredd series and 11 novels and a novella collection in the Legends of Lone Wolf series; edited several anthologies, beginning with Aries 1 (1979) and most recently the major anthology New Writings in the Fantastic (2007); and has written or collaborated on dozens of non-fiction works, including several relating to fantasy and science fiction. His collaborators have included David Langford and, as illustrator, Bob Eggleton. With John Clute, he co-edited The Encyclopedia of Fantasy (1997) for which he also wrote all the cinema entries."
Source: Wikipedia, "John_Grant_(author)", available under the CC-BY-SA License.
Note: This person should not be confused with Paul Barnett (born 1970), an English game designer most often associated with Games Workshop, John Grant (born 1933), an English crime writer and doctor who served in the Royal Army Medical Corps, or John Gildroy Grant or John Duncan Grant, soldiers who were awarded the Victoria Cross, the highest award of the British Commonwealth.