Question: In which year did the artist, who illustrated "Multiverse: Exploring Poul Anderson's Worlds" win the Chesley Award for Artistic Achievement?
Context: The Robert Chesley Award was an annual literary award, presented by Publishing Triangle to honour drama works by playwrights in the LGBT community.  First presented in 1994, the award was named in memory of playwright Robert Chesley.  The award was discontinued in 2008. "Quest" is a science fiction novelette by American writer Poul Anderson, about the consequences of an extraterrestrial scoutship landing in Medieval England.  It is a sequel to Anderson's 1960 novel "The High Crusade".  Poul Anderson described the original as "one of the most popular things I've ever done, going through many book editions in several languages."  "Quest", originally appeared in "Ares" magazine in the same issue that saw the original publication of" The High Crusade" wargame.  The novelette was included in two collections of Anderson's short work, "Space Folk" and "Going for Infinity", before being added to the Baen Books fiftieth anniversary edition of "The High Crusade". Julie Dillon (born in 1982) is an American artist specializing in science fiction and fantasy art.  A freelance illustrator, Dillon has created images for games, book and magazine covers, and covers for musical albums.  Dillon's work has been nominated for the Chesley Award three times; she won the 2010 Chesley Award for Best Unpublished Color for "Planetary Alignment" (subsequently published as a cover for "Clarkesworld Magazine"), as well as the 2011 Chesley Award for "The Dala Horse" in Best Interior Illustration.  She was nominated for the World Fantasy Award for Best Artist in 2012 and received the Hugo Award for Best Professional Artist in 2014, 2015, and 2017.  She also received two Chesley Awards in 2015 for the Best Cover Illustrations for a magazine and a hardback book.  Dillon lives and works in California. Don Maitz is an American science fiction, fantasy, and commercial artist.  His most widely known creation is the "Captain" character of the Captain Morgan brand of rum, although he is perhaps most notable for twice winning the Hugo Award for Best Professional Artist, science fiction's highest honor for an artist.  His peers in the Association of Science Fiction and Fantasy Artists have honored him ten times with a Chesley Award for outstanding achievement, and he has received a Silver Medal of Excellence from the Society of Illustrators. The High Crusade is a science fiction novel by American writer Poul Anderson, about the consequences of an extraterrestrial scoutship landing in Medieval England.  Poul Anderson described the novel as "one of the most popular things I've ever done, going through many book editions in several languages." Bobera Eggleton (born September 13, 1960) is an American science fiction, fantasy, and horror artist.  Eggleton has been honored with the Hugo Award for Best Professional Artist eight times, first winning in 1994.  He also won the Hugo Award for Best Related Book in 2001 for his art book "Greetings From Earth".  He has also won the Chesley Award for Artistic Achievement in 1999 and was the guest of honor at Chicon 2000. The Best of Poul Anderson is a collection of writings by American science fiction and fantasy author Poul Anderson, first published in paperback by Pocket Books in August 1976.  It was reprinted in August 1979.  The pieces were originally published between 1953 and 1970 in the magazines "Astounding Science Fiction", "Analog", "Galaxy Magazine", and "The Magazine of Fantasy and Science Fiction", and the anthology "The Farthest Reaches". The Chesley Award for Lifetime Artistic Achievement is given by the Association of Science Fiction and Fantasy Artists (ASFA) to recognize the achievements of a science fiction or fantasy artist for work over their entire careers. The Many Worlds of Poul Anderson is a collection of science fiction short stories by American writer Poul Anderson, edited by Roger Elwood, first published in hardcover by Chilton in June 1974.  A paperback edition retitled The Book of Poul Anderson followed from DAW Books in June 1975, and was reprinted in June 1978, December 1978, and October 1983.  Most of the pieces were originally published between 1947 and 1971 in the magazines "Astounding Science Fiction", "The Magazine of Fantasy and Science Fiction", "Analog", "Riverside Quarterly", and "Other Worlds Science Stories".  The others are original to the collection. Multiverse: Exploring Poul Anderson's Worlds is a gedenkschrift honoring science fiction and fantasy author Poul Anderson, in the form of an anthology of short stories and tributes edited by Greg Bear and Gardner Dozois.  The book also includes cover art and interior illustrations by Bob Eggleton.  It was first published in hardcover in May 2014 by Subterranean Press, with simultaneous paperback and ebook editions issued in June 2015 by Baen Books.  All but one of the pieces are original to the anthology; the remaining one, Tad Williams's "Three Lilies and Three Leopards (And a Participation Ribbon in Science)", was originally published in the Winter 2012 issue of the ejournal "Subterreanean Online".
Answer: 1999