MAJOR SPOILERS for Aftermath: Empire's End follow
The first act of Star Wars: The Force Awakens is primarily set on the desert wasteland Jakku, a planet very reminiscent of the classic world Tatooine. From the outset, it was clear Jakku was more than just a stand-in for the Skywalkers' home planet. Imagery depicted the aftermath of a great battle waged between the New Republic and the Empire in the time after Return of the Jedi, leaving many wrecked ships scattered across the landscape. Scavengers search these vehicles for parts they can sell for food, and Rey even calls a fallen AT-AT home as she waits for her family to return.
As presented in Episode VII, the destruction on Jakku was a clear indicator not everything was so happy-go-lucky following the Battle of Endor, and the galaxy remained embroiled in conflict. For those curious, Lucasfilm's story group told the story of what happened in the video game Star Wars: Battlefront, which included a Battle of Jakku playable map. But for fans uninterested in gaming, the full story of the confrontation is the driving force behind the recently-published novel Aftermath: Empire's End. Simply based on the book's cover, it was apparent Jakku would factor heavily into the narrative, and now readers can learn how it all went down. Here's the Battle of Jakku, explained.
Why is the Empire on Jakku?
In the Aftermath trilogy by author Chuck Wendig, the surviving remnants of the Empire fall under the leadership of Admiral Gallius Rax, who was handpicked by Palpatine to be his Contingency. Rax was born on Jakku and grew up in its harsh conditions. Though he longed for a more luxurious life (and received it by joining the Imperials), Rax's tumultuous youth helped mold him into the harsh, determined officer he is in the present day. Jakku is a planet of some importance to Palpatine, and prior to his death, he placed Rax in charge of the Observatory there (more on this in a minute) so Rax could make final preparations. Gallius amasses a sizable Imperial fleet, consisting of star destroyers, TIE fighters, and walkers.
For most of Empire's End, Rax hopes to use the living conditions on Jakku to craft a more ruthless Empire that can potentially be better than Palpatine's. His true intentions are left quite vague until the book's third act, where it is revealed Rax is to take a replica of Palpatine's personal ship (in the company of Brendol Hux and his army of trained child soldiers) and join the others loyal to the Emperor in the unknown regions of the universe. There, these traces of the old Empire will find a new galaxy to rule - not exactly succeeding Palpatine (whose own ego would not allow anyone else to rule the galaxy far, far away), but still honoring his teachings and legacy.
In essence, the Empire takes refuge to Jakku as a ruse to draw the New Republic out so a battle can be waged. When the fighting starts, Rax is to go to the Observatory and activate a self-destruct device on Jakku, destroying the planet and eliminating both the old regime and the newly-formed Republic. However, Republic leadership is unaware of Rax's duplicitous desires, and sees a golden opportunity to deliver their enemies one final, crushing blow and end the Galactic Civil War for good. Only, organizing an attack isn't as easy as it was in the days of the Rebel Alliance.
New Republic Politics
When the Republic discovers a heavy Imperial presence on Jakku, support grows for their fleet to assemble and take the Empire out. In particular, members of Nora Wexley's crew (including her son Temmin) are eager to fight, since Nora and her friend Jas Emari are stranded on the surface after they went to investigate. But whereas the Rebellion would be able to simply gather what ships they had and go (much like the Resistance in this regard), the New Republic has official procedures that need to be followed before military action can take place. This doesn't sit well with everyone, but it's a necessary component of re-establishing the democracy.
Chancellor Mon Mothma (who is normally more of a pacifist) calls for a vote in the Senate to move forth with an offense on Jakku, fearing what might happen if the Empire reforms. Unfortunately, the vote fails by a count of five, and the Republic fleet is forced to stand still. However, Mon has a plan to ensure things will go her way when the re-vote happens. As Mon stalls the Senate session from taking place (causing a harmless inspection on her rival Senator Wartol's ship), a group of Republic spies - including Han Solo - track down the five senators in question so they can convince them to change their votes. Learning criminal organizations have leverage on the senators, the Republic spies help reverse those fortunes, and the re-vote passes. This allows the Republic to launch their strike.
This process more or less underscores why Leia decided to form the Resistance prior to the events of the sequel trilogy. It's already been established the Resistance is an offshoot group under Leia's command, a fact that gives the Princess some enemies in the government. An advantage the Resistance has over an official Republic army is that it can act more like the Rebel Alliance and isn't dependent on the approval of bureaucrats to quell perceived threats to galactic freedom. Granted, this makes Leia a bit of a pariah and hurts her reputation in some circles, but as the First Order rises, waiting around doesn't sound like the best option. It's a complex dynamic that hopefully will be explored more in The Last Jedi this winter.
Fall of an Empire
Whether it be Scarif, Yavin, or Endor, moviegoers have seen the Empire take its fair share of hits over the years. However, the Imperials were so well-resourced, they were able to bounce back - even after losing Palpatine and Vader. That said, Jakku is a different matter. It is here where the Galactic Civil War comes to a bloody and destructive end, in a battle that reads as thrilling and exciting anything viewers watched on the big screen. Similar to Return of the Jedi, there's a space dogfight in addition to an overwhelming ground assault involving infantry, walkers, and Rebel fighters soaring through the air. It goes without saying that not all of the Aftermath main characters make it out alive (including the shocking and upsetting death of beloved droid Mr. Bones). As Rax initiates Jakku's self-destructing device, the Republic and Empire tear each other apart.
Whatever's left of the Empire threw everything they had into Jakku, and they're dealt a massive blow when the super star destroyer Ravager is pulled down to the planet's surface and destroyed. That is essentially the end of the battle, as the Imperials are left without their command ship. However, there's still the matter of Jakku's stability, and obviously, the planet is saved from complete annihilation. Ex-Imperial admiral Rae Sloane shut down the device before departing for the Unknown Regions with Hux herself. Sloane delivered the killing blow to Rax, a viscous act of revenge against Gallius for usurping command of her Empire. Rae is a fervent believer in the order of Palpatine's regime and hopes to mold a new empire in her doing.
The final act of the war, as it usually is in real life, is the signing of a ceasefire/treaty. Palpatine's former advisor Mas Amedda comes out of hiding and surrenders to the Republic. As part of the arrangement, the fighting is to stop immediately and the old Imperial government is dissolved permanently. The Imperial officers who survived are labeled as "war criminals," but those of non-combatant nature are given pardons. Despite this, there are still some small traces of the Empire, but they are too minuscule to pose a serious threat to the blossoming Republic. The Battle of Jakku continues on for a period of months, but it eventually ends, and a period of (hopeful) peace can begin as the galaxy heals.
It's worth pointing out that there are some small inconsistencies between the portrayal of the Battle of Jakku in Empire's End and some other canon materials. The novel Lost Stars depicts this mighty struggle at its end, and main character Ciena Ree notes her Empire is losing because they are stubbornly sticking to the old combat formations. However, in Empire's End, Rax's forces are noted for their unpredictable fighting style, which makes matters difficult for Admiral Ackbar and the Republic. Additionally, the Battlefront DLC suggested the discovery of an Imperial weapons depot led to the Republic attack. In the new book, it's simply the sight of a huge Imperial fleet gathered around the planet that serves as the catalyst.
While odd, these discrepancies aren't nearly enough to detract from seeing the whole battle unfold and learning how Jakku was the center for one of the galaxy's defining events. It was there the New Republic was truly born, the old Empire ended, and the seeds for the First Order were planted (via Palpatine's Contingency). For a backwater, remote planet with little to offer other than scorching temperatures and a mundane life, that's quite a role to play in the history books.
Source: Aftermath - Empire's End