Question: In which year was the first of the vampire-themed fantasy romance novels for which The Twilight Saga: The Official Illustrated Guide serves as a spin-off encyclopedic reference book first published?

Context articles: Monuments of Athens
A Guide to Middle-earth
The Twilight Saga (film series)
Tagalog pocketbooks
The Guide to Modern World Literature
The Dark Heroine
The Twilight Saga: The Official Illustrated Guide
Fragrances of the World
Twilight (novel series)
List of Twilight cast members

Monuments of Athens (Greek: Μνημεία Αθηνών) is a book first published in 1924 by the Greek archaeologist Alexander Philadelpheus.
 It consists of an illustrated guide to the city of Athens, its museums and sites of interest expanding throughout the ancient Greek history and monuments of the city up to the "modern" times of the original author.
A Guide to Middle-earth was the first published encyclopedic reference book for the fictional universe of J. R. R. Tolkien's Middle-earth, compiled and edited by Robert Foster.
 The book was published in 1971 by Mirage Press, a specialist science fiction and fantasy publisher, in a limited edition of 2000 copies (750 numbered hardcovers and 1250 unnumbered paperbacks).
 A paperback edition was issued by Ballantine Books in 1974.
The Twilight Saga is a series of five romance fantasy films from Summit Entertainment based on the four novels by American author Stephenie Meyer.
 The films star Kristen Stewart, Robert Pattinson, and Taylor Lautner.
 The series has grossed over $3.3 billion in worldwide receipts and consists, to date, of five motion pictures.
 The first installment, "Twilight", was released on November 21, 2008.
 The second installment, "", followed on November 20, 2009, breaking box office records as the biggest midnight screening and opening day in history, grossing an estimated $72.7 million.
 The third installment, "", was released on June 30, 2010, and was the first "Twilight" film to be released in IMAX.
According to Tatin Yang in the article "Romansang Pinoy: A day with Tagalog romance novels", Tagalog romance paperbacks were thin Philippine versions of romance novel books that could be found at the bottom shelves of the romance section of bookstores, wrapped and bound with book covers that are decorated with Philippine comics-styled illustrations, such as "a barrio landscape with a badly dressed guy and girl locked in an embrace".
 As a form of "escapist fiction" (escapism) and "commercial literature", Tagalog romance novels generally follow a "strict romance formula", meaning the narratives have happy endings (a factor influencing the salability of the novel), the protagonists are wealthy, good-looking, smart, and characters that cannot die.
 Normally, the hero or heroine of the story falls in love and "goes crazy" over the admired person.
 However, later authors of Tagalog romance novels deviated from portraying so-called "damsel-in-distress and knight-in-shining-armor characters".
 Contemporary writers also turned away from writing "rags-to-riches plots".
 The stereotypical norm had been replaced by the incorporation of storylines with "interesting scenes, characters [who are ready to face challenges or to sacrifice themselves for the benefit of other people], dialogues, and new angles to old plots".
 Authors such as Maria Teresa Cruz San Diego, who used the pen names Maia Jose and Tisha Nicole, ventured into the fantasy romance genre, and into topics that are related to politics, ecology, gender issues, prostitution, mail-order bride syndicates, white slavery, non-governmental organizations, and breastfeeding programs.
 Apart from writing about ideal lovers (men and women) and ideal situations, other novelists wrote about true-to-life settings, or at least based the stories from personal experiences.
 Thus, Tagalog romance novels came to mirror or replicate the "roles that women and men play" in Philippine society.
The Guide to Modern World Literature is a reference book by Martin Seymour-Smith that aims to describe every important 20th-century author (as of 1985), in all languages, in an encyclopedic presentation.
 It was first published in 1973 with a completely revised and updated version in 1985 called The New Guide to Modern World Literature.
The Dark Heroine is a series of vampire-themed fantasy romance novels written by English author Abigail Gibbs, published by HarperCollins in 2012.
 The first novel in the series, "Dinner with a Vampire," revolves around London-born Violet Lee, who is kidnapped and held hostage by a Royal Family of vampires known as the Varns.
 The series is told from both Violet Lee and Kaspar Varn's perspective, the latter being heir to the Vamperic Throne in the novel.
The Twilight Saga: The Official Illustrated Guide (previously titled The Official Guide) is a spin-off encyclopedic reference book for the "Twilight Saga" book series, written by Stephenie Meyer and was released on April 12, 2011.
 "The Guide" includes exclusive new material about the world Meyer created in "Twilight", "New Moon", "Eclipse", "Breaking Dawn" and "The Short Second Life of Bree Tanner", and nearly a hundred full-color illustrations by illustrator Young Kim, who previously illustrated Meyer's #1 "New York Times" Best Seller "", and several other artists.
Fragrances of the World is the largest independent guide to fragrance classification.
 First published in 1984 by Michael Edwards in Sydney, Australia, the guide was originally named "The Fragrance Manual" before becoming "Fragrances of the World" in 2000.
 It has since been printed annually in a bilingual English-French edition.
 An online companion, the "Fragrances of the World" database, was launched in 2004 and, as of 2015, profiles over 17,000 perfumes, updated weekly.
 "Fragrances of the World" is considered a standard encyclopedic reference within the fragrance industry, colloquially termed the “"Fragrance Bible"” (a registered trademark since 2011).
Twilight is a series of four vampire-themed fantasy romance novels by American author Stephenie Meyer.
 Released annually from 2005 through 2008, the four books chart the later teen years of Isabella "Bella" Swan, a girl who moves to Forks, Washington, and falls in love with a 104-year-old vampire named Edward Cullen.
 The series is told primarily from Bella's point of view, with the epilogue of "Eclipse" and Part II of "Breaking Dawn" being told from the viewpoint of character Jacob Black, a werewolf.
 The unpublished "Midnight Sun" is a retelling of the first book, "Twilight", from Edward Cullen's point of view.
 The novella "The Short Second Life of Bree Tanner", which tells the story of a newborn vampire who appeared in "Eclipse", was published on June 5, 2010, as a hardcover book and on June 7 as a free online ebook. ""
, a definitive encyclopedic reference with nearly 100 full color illustrations, was released in bookstores on April 12, 2011.
This is a list of the cast members from The Twilight Saga film series, which is based on the novels by Stephenie Meyer.
 The main stars of the films are Kristen Stewart as Bella Swan, Robert Pattinson as Edward Cullen, and Taylor Lautner as Jacob Black.
 "Twilight" (2008) is based on the "New York Times" best selling novel of the same name (2005) and was directed by Catherine Hardwicke.
 The second film, "" (2009) is based on the first book's sequel (2006).
 It was directed by Chris Weitz.
 The third film, "", directed by David Slade, was released on June 30, 2010.
 and is based on the third installment in the series (2007).
 The filming of Breaking Dawn pt 1 started on November 1, 2010.
 The Twilight Saga: Breaking Dawn – Part 1 (commonly referred to as Breaking Dawn – Part 1) released in theatres on November 18, 2011, and released to DVD on February 11, 2012 in the United States.
 The film grossed over $712 million worldwide.
 The Twilight Saga: Breaking Dawn – Part 2 (commonly referred to as Breaking Dawn – Part 2) was released on November 16, 2012, by Lionsgate in the United States, in consequence of the merger between Lionsgate and Summit Entertainment.
 The film (101 days in release) was a box-office success, grossing over $829 million worldwide, becoming the 34th highest-grossing film, the 6th highest-grossing film of 2012 and the highest-grossing film of the Twilight series.