f you felt a great disturbance in the Force this Friday, that's because there are major changes afoot in the Star Wars universe.

Lucasfilm has announced that all of the books and comics that filled the empty space in the Skywalker story after Return of the Jedi in 1983, hundreds of titles collectively known as the Expanded Universe, will no longer play any part in official Star Wars canon — and they won't stand as precursors to the upcoming movies.

"In order to give maximum creative freedom to the filmmakers and also preserve an element of surprise and discovery for the audience, Star Wars Episodes VII-IX will not tell the same story told in the post-Return of the Jedi Expanded Universe," says the official announcement on Starwars.com.

What does that mean? Well, for one thing, the multimillion-selling trilogy by author Timothy Zahn — which started with the no. 1 New York Times bestseller Heir to the Empire in 1991 — no longer happened. Neither its much beloved Imperial villain Grand Admiral Thrawn, nor the popular former assassin Mara Jade, future wife to Luke Skywalker, officially existed in the Star Wars timeline.