The Star Wars expanded universe (SWEU; formerly branded as Expanded Universe or EU) is a collective term for all Star Wars fictional material produced by Lucasfilm or officially licensed by it. This expanded universe includes an array of derivative Star Wars works produced in conjunction with, between, and after the original trilogy (1977–1983) and prequel trilogy (1999–2005) of films, and includes books, comic books, video games, and television series. Intended as an enhancement to and extension of the Star Wars theatrical films produced by George Lucas, the continuity of all Expanded Universe material was tracked by Lucasfilm, and Lucas reserved the right to both draw on it and contradict it in his own works.
The Star Wars space opera media franchise began with Lucas's 1977 film Star Wars, which is set "a long time ago in a galaxy far, far away" and chronicles the attempt by the characters Luke Skywalker, Princess Leia, Han Solo, and the Wookiee Chewbacca—assisted by the Jedi Obi-Wan Kenobi and the droids C-3PO and R2-D2—to thwart the evil plans of Sith Lord Darth Vader and the Galactic Empire.