The Star Wars Expanded Universe consists of all officially licensed materials other than the six Star Wars films. A variety of different media make up the EU, including novels, comics, movies, video games, action figures, and television series. Its history begins soon after the premiere of the first Star Wars films, although it did not reach the form we know today until the early 1990s. Today, the Expanded Universe spans five millennia and contains media for every type and age of fan, from Ewok picture books to the dark and violent Legacy of the Force and Dark Times.
The Beginnings of the Expanded Universe
The earliest Expanded Universe material were Star Wars comics published by Marvel. Pizzazz magazine, which premiered in October 1977, contained a serialized Star Wars comic, "The Keeper's World." Although adaptations of the first Star Wars film had already been published, this comic was the first Star Wars story that went beyond the movies.
The first six issues of the comic Marvel Star Wars contained an adaptation of A New Hope, but it too began presenting original stories beginning with Issue #7, "New Planets, New Perils," published in January 1978. February 1978 brought the first Expanded Universe novel: Splinter of the Mind's Eye, by Alan Dean Foster. In November 1978, the Star Wars Holiday Special marked the first Expanded Universe material for television. Despite being infamously terrible, it contributed ideas and characters to future films and EU works, including Chewbacca's family, the Wookiee planet Kashyyyk, and the bounty hunter Boba Fett.
Many aspects of the early Expanded Universe seem very different from later works (and even later movies). The early stories predate Lucasfilm's attempt at an organized and consistent Star Wars continuity, and frequently contradict later materials, both in small ways (Foster referring to R2-D2 as a "detoo" rather than "artoo" unit) and large ways (Marvel Star Wars publishing a comic establishing Anakin Skywalker and Darth Vader as two separate people).
As a result, these early Expanded Universe works are a lower level of canon than works that came later. The Marvel Star Wars comics are considered non-canon (that is, they never really happened in the Star Wars universe) unless another EU work refers to their events. A number of stories from Marvel Star Wars have become important in recent years, however; for example, Lumiya, a dark side user who first appeared in the Marvel Star Wars story "Coffin in the Clouds," became a major player in the Legacy of the Force novels as Jacen Solo's Sith Master.
The Turning Points of the Expanded Universe
Throughout the 1980s, the EU gradually expanded. Marvel Star Wars continued until 1986 and several more novels were published: The Han Solo Adventures by Brian Daley and The Lando Calrissian Adventures by L. Neil Smith. The popularity of the Ewoks led to two Ewok Adventure movies and a cartoon series, and R2-D2 and C-3PO got their own cartoon and comics about their adventures before A New Hope. West End Games, in their Star Wars role-playing guides, began to develop details of the Star Wars universe that had not been addressed in the films. Still, the question of what happened after Return of the Jedi remained largely unexplored.
This all changed in 1991 with the publication of two monumental works: Heir to the Empire and Dark Empire. Timothy Zahn's novel Heir to the Empire, published in June 1991, was the first Expanded Universe novel taking place after Return of the Jedi. Along with its sequels, Dark Force Rising and The Last Command, the novel followed the characters from the Star Wars films as their new government, the New Republic, struggled against the remnants of the Empire. The comic Dark Empire, whose first issue premiered in December 1991, takes place a year after Zahn's Thrawn Trilogy and deals with the return of Emperor Palpatine.
The Thrawn Trilogy and Dark Empire opened the floodgates for the Expanded Universe we know today. Over the course of the 1990s, the EU explored the continuing adventures of the Star Wars characters as they attempted to rebuild both the Republic and the Jedi Order. In the course of the EU's development, authors paid great attention to detail and continuity. Characters and events in different media reference and affect each other: for example, Luke turning to the dark side in Dark Empire has major consequences for his character in the Jedi Academy novels, and Mara Jade (introduced in The Thrawn Trilogy) becomes the apprentice of Kyle Katarn (and a playable character) in the Dark Forces video games.
One area was still off-limits, however: the era of the Star Wars Prequels. George Lucas was still planning to make Episodes I, II, and III, and so any media which addressed characters and events from that era was sure to be contradicted by future films. Authors made up for the loss by exploring even further into the history of the Galaxy Far, Far Away. The Tales of the Jedi comic Golden Age of the Sith is the earliest EU story, taking place 5,000 years before A New Hope and examining the history of the Sith Empire.
The Expanded Universe reached another turning point in 1999 when the license for Star Wars novels transferred from Bantam to Del Rey. The Bantam Era had concluded with two more novels by Timothy Zahn, Specter of the Past and Vision of the Future, which neatly wrapped up the conflict between the New Republic and the Imperial Remnant, and the Star Wars universe needed a new enemy to move forward. The novel Vector Prime, by R.A. Salvatore, kicked off the New Jedi Order Era and introduced the Yuuzhan Vong, a race of extra-galactic, technophobic aliens who invade the Star Wars galaxy.