Twenty years ago Star Wars began its true second act. Not on the big screen, mind you, or the tube, but in print. It was eight years after Return of the Jedi, eight before The Phantom Menace, and while George Lucas was still filling legal pads full of notes about Gungans and midichlorians, author Timothy Zahn published Heir to the Empire and forever changed the way fans thought about that Galaxy Far, Far Away.

Rather than fill-in backstory to tales fans already knew, as earlier novels like Brian Daley’s Han Solo Adventures had done, Zahn set his cosmic yarn five years AFTER Return of the Jedi, then a completely unexplored part of the Star Wars timeline. Fans of the movies found out that, no, the Empire was not defeated overnight with the death of Emperor Palpatine and the destruction of the Second Death Star—in spite of that Jedi-capping orgy of drunken Ewoks. In fact, though the Rebel Alliance had become the New Republic and controlled half the galaxy from the Empire’s former capital at Coruscant (which Zahn himself named), the Imperial Navy was set to launch perhaps its greatest onslaught ever—led by the blue-skinned, red-eyed, art-loving master tactician Grand Admiral Thrawn.

Unlike Vader and Palpatine, Thrawn was no Manichaean symbol of evil, but an incredibly charismatic and even sympathetic foe—Erwin Rommel crossed with Sherlock Holmes—but just as deadly. Heir to the Empire was the first of three novels penned by Zahn (the others being Dark Force Rising and The Last Command) that charted Thrawn’s war against the New Republic and delved deep into his dizzying array of tactics, like blockading Coruscant with asteroids rendered invisible by cloaking devices; finding a presumed-mythical fleet of Old Republic-era dreadnaughts thought lost after their crews went mad; employing Force-blocking ysalamiri to repel Jedi; even going so far as to clone Luke Skywalker from the hand Vader cut off on Cloud City. Remember that creepy, dream-like vision Luke receives on Dagobah about fighting himself in The Empire Strikes Back? Consider that a portent of what happens for real at the end of The Last Command.

Previous Star Wars novels had tried to capture the quirky, retro thrills of the movies, harkening back to ’30s Flash Gordon serials and Saturday morning cartoons. The Thrawn Trilogy, for all its operatic flair, grounded Star Wars in a new, more tactile reality, taking that “used universe” concept from the movies to its lived-in limit, while populating that world with terse military brass and haunted anti-heroes, like the Eastwood-esque smuggler Talon Karrde (who always shoots first) and Mara Jade, the crimson-haired former Emperor’s Hand hell-bent on assassinating the baby-faced Rebel she suspects killed her master, Palpatine: one Mr. Luke Skywalker. Jade defined a new breed of tough-talking, no-nonsense sci-fi heroine years before Katee Sackhoff’s Starbuck brawled and imbibed her way into fangirls’ hearts. And even as she was trying to kill Luke, you just knew she was the only woman for him.

Poll any diehard Star Wars fan, and he or she will tell you that if George Lucas ever gets around to making a “sequel” trilogy, it should be an adaptation of Zahn’s three-book opus. Why? It was the characters that above all made Heir to the Empire and its follow-ups such a geeky treat—after all, what was Thrawn’s greatest weapon? His intellect.—and it launched what we now know as the Expanded Universe: dozens of novels, ebooks, and comics set up to 130 years after the original Star Wars and 5,000 years before it, like the 19-book New Jedi Order series that saw a fanatical extra-galactic alien horde invade the Star Wars galaxy or the current Fate of the Jedi series, many of which still crack the New York Times Bestsellers List, which Heir to the Empire topped 20 years ago.

Now, to celebrate the anniversary, Del Rey Books has released a 20th anniversary re-issue of Heir with annotations from Timothy Zahn himself about the creation of his epic. Here are three EW’s been authorized to reprint in their entirety:

Zahn on the greatest compliment Grand Admiral Thrawn’s ever received and whether he could have defeated the Rebels at Endor:

“I think the greatest compliment Thrawn has ever received came from a U.S. serviceman. (I can’t remember if he was a soldier or Marine.) He told me he and his buddies had read the Thrawn Trilogy, and had agreed that they would unreservedly follow a commander like Thrawn. Oh, and what would have happened if Thrawn had been in command at Endor? The Rebels, in my humble opinion, would almost certainly have lost.”

On how he came up with a literary shorthand to describe a lightsaber’s iconic sound:

“I thought long and hard about how to write the sound of an igniting lightsaber. I finally went with snap-hiss.”

On the creation of Mara Jade:

“Mara Jade’s creation began with a simple idea and plan: to tie the opening section of Return of the Jedi more closely to the main story presented by the Star Wars movies.

To elaborate a bit. Han’s rescue was, of course, a vital part of Jedi. But to me, it always felt a little disconnected from the main Rebellion plot line. (Which it was, of course. Rescuing Han was strictly personal, on everyone’s part.)

As I mulled it over, it occurred to me that, after Vader’s attempt to persuade Luke to join him in The Empire Strikes Back, the Emperor might very well have decided that Luke was more liability than potential asset and sent someone to take him out when he turned up at Jabba’s palace.

What kind of person might Palpatine send? It would have to be someone competent, naturally. It would also have to be someone who could meet Luke’s Jedi power head-on. Finally, it would have to be someone who was out of the normal chain of command, lest Vader get wind of the plan.

From all that came the idea of the Emperor’s Hand, a shadowy agent under Palpatine’s sole command. And from that, ultimately, came Mara Jade.”

Did you read Heir to the Empire when it first came out? If so, have you followed the Expanded Universe in the two decades since? And is Zahn’s Thrawn Trilogy still the apex of the Expanded Universe?

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