The Battle of Kashyyyk, also referred to as the Kashyyyk subjugation, marked the initial Imperial invasion targeting the Wookiee homeworld of Kashyyyk in 19 BBY, a year that saw the beginning of the Empire's Enslavement of Kashyyyk campaign. This conflict unfolded after the Dark Lord of the Sith, Darth Vader, located a group of surviving Jedi on the planet. It was during this crisis that Vader struck a bargain with Moff Tarkin to seize Wookiees for slave labor, crucial for the construction of the Death Star. This battle served as an early indication to the galaxy of the harsh response the Galactic Empire would employ against any internal opposition, though it was not the last.
In the wake of the catastrophic Order 66, Jedi Padawan and survivor Olee Starstone embarked on a quest to find any remaining Jedi.
One of the planets she investigated was Kashyyyk, where Masters Yoda, Luminara Unduli, and Quinlan Vos had been stationed when Order 66 was executed. She arrived on the planet alongside other Jedi survivors – Siadem Forte, Deran Nalual, Klossi Anno, Iwo Kulka, Jambe Lu, and Nam Poorf, as well as the slicer Filli Bitters. After their meeting with Tarfful and Chewbacca, the Jedi learned that Yoda had survived. The Wookiees extended an offer of sanctuary to the Jedi group on Kashyyyk, but their meeting was disrupted by the arrival of a CR25 troop carrier at Kachirho.
Shortly after the Jedi's arrival, the Dark Lord of the Sith Darth Vader arrived in the Kashyyyk system aboard the Imperator-class Star Destroyer Exactor, where he rendezvoused with Wilhuff Tarkin and the Executrix. Together, they plotted their assault on Kashyyyk—Vader sought to hunt down and eliminate the fugitive Jedi, while Tarkin aimed to enslave the Wookiees for labor on the first Death Star construction.
Around this time, the night preceding the main Imperial attack, Tarkin deployed a platoon of stormtroopers under Captain Janzor as a diversionary tactic. Although all but three troopers perished due to a combination of a crash, unforeseen hostile wildlife, and underestimation of the Wookiees, they successfully distracted the Wookiee forces, allowing the main Imperial force to conquer an entire continent.
While the fleet commanders advocated for bombarding the planet, Vader overruled them, instead mandating a direct assault on several cities, including Kachirho, Rwookrrorro, Kepitenochan, Okikuti, and Chenachochan.
At Kachirho, the invading Imperial troops demanded the Wookiees surrender the fugitive Jedi, but the enraged Wookiees retaliated, and Starstone and her Jedi companions quickly joined the fray. As more Imperial forces landed, the Wookiee warriors and the Jedi provided cover for the evacuation of Kachirho, as countless Wookiees fled the Imperial troopers to avoid enslavement. Oevvaor jet catamarans, retrofitted with rocket launchers and other advanced military hardware salvaged from the wreckage of the earlier Battle of Kashyyyk, engaged Imperial landers and gunships. Recognizing the indiscriminate nature of the Imperial attack, many traders and merchants present began evacuating Wookiee families, while others employed concealed weapons on their vessels to target various Imperial transports. By this point, all troopers from the initial wave had been eliminated.
Approximately one local hour after the start of the attack, Lord Vader descended to Kachirho in a Theta-class T-2c shuttle in an attempt to hunt down the Jedi. He was accompanied by Commander Appo and a squad of troops, but encountered significant anti-aircraft fire during his descent. Across the planet, fierce Wookiee warriors were repelling the Imperial incursions, and the assaults were resulting in an alarming number of Imperial casualties. Following Appo's suggestion, Vader granted the fleet commanders permission to initiate orbital bombardment, but cautioned them to spare Kachirho until last.
Upon landing on a platform high within Kachirho, Vader and his stormtrooper contingent disembarked and began battling their way through the Wookiee warriors.
To prevent further Wookiee deaths, the Jedi revealed themselves. Olee Starstone had separated from Roan Shryne, who had since joined his mother's ship, the Drunk Dancer, now leading a group of surviving Jedi they had located. Vader instructed the stormtroopers to focus on the Wookiees, leaving the Jedi to him. Siadem Forte and Iwo Kulka immediately attacked Vader, attempting to destabilize him with contrasting lightsaber forms. However, Vader easily defended himself, employing a combination of precise bladework and swift power attacks to end their elaborate movements, leveraging his superior height and strength to disrupt their momentum and send them staggering. Vader decapitated the two Jedi, and quickly disabled Jambe Lu, Nam Poorf and Klossi Anno.
Olee Starstone suddenly found herself alone against the Sith Lord. Starstone attempted to overwhelm Vader with a sudden offensive, but realized that Vader was merely allowing her to exhaust herself. Breaking off to reassess her strategy, she inadvertently allowed Vader to seize the offensive. However, before he could defeat Starstone, Vader's Stormtroopers were suddenly eliminated by a smuggler vessel that had just arrived. Roan Shryne leaped off the Drunk Dancer, summoning Siadem Forte's lightsaber to his hand and beheading Appo. Confronting Vader, Shryne provided Starstone and the other surviving Jedi with a chance to escape.
As the two engaged in combat, Shryne managed to hold his own against Vader's relentless assault, even landing several hits. However, their battle was interrupted by the Imperial orbital bombardment.
As Shryne and Vader fought, the main battle began to shift east of the city, moving towards the lake, as Imperial gunships and artillery forced the Wookiees out of the city and onto the ground. Heading to the main Kachirho landing platform, Archyr and Starstone loaded their dropship and transport with escaping Wookiees, including Chewbacca.
Suddenly, the Imperial gunships began to withdraw from Kachirho, as the orbiting Star Destroyers commenced their orbital bombardment. Shryne and Vader's duel was interrupted by the strike, and the two sought refuge inside one of the great wroshyr trees. Although they both survived, Vader's shuttle was destroyed by the flak. As their battle resumed, Shryne deduced that the chest-mounted control panel was the weakness of Vader's suit. His attempts to target the panel forced Vader to adopt a defensive fighting style that left his limbs exposed, ultimately compelling him to resort to a telekinetic assault. Tearing apart the wooden ramps and platforms within Kachirho, Vader hurled the debris at the hapless Jedi, battering him and knocking him off the platform on which they fought.
Lying critically injured on a floor below, Shryne was helpless. Certain that Shryne was going to die anyway, Vader chose not to kill the Jedi, instead revealing his true identity to the man—Anakin Skywalker, who was later redeemed by his son Luke Skywalker during the Battle of Endor in 4 ABY.
As Shryne died, Victory-class Star Destroyers began to descend into the atmosphere, completing the conquest of Kashyyyk. Approximately two hundred thousand Wookiees, including Tarfful, were captured and relocated to containment camps on the Wawaatt Archipelago.
Meanwhile, having escaped Kashyyyk, Starstone and the surviving Jedi met up with the Drunk Dancer in orbit, where they discovered that a Detainer CC-2200 interdictor cruiser was stationed over Kachirho, preventing ships from entering hyperspace from that city. Undeterred, Starstone and Bitters devised a plan to destroy it in order to escape. With assistance from Chewbacca, Archyr, Cudgel, and the rescued Wookiees, the pair managed to reactivate a damaged Recusant-class light destroyer, a Separatist ship left over from the earlier battle weeks ago. The group fought their way through the ship's reactivated battle droids and reached the bridge.
They instructed the droid-controlled destroyer to ram the Interdictor, destroying it and allowing the transports trapped in orbit around Kashyyyk a chance to escape.
Enraged by this, Lord Vader ordered a complete orbital bombardment of the planet.
Tarkin would later inform Palpatine that the planet had sustained considerably more damage than expected, especially considering the resources at Vader's disposal. Nevertheless, Kashyyyk had been seized by the Empire, and Tarkin—possibly with the help of Trandoshan slavers who arrived on the world en masse after the battle—had acquired a valuable new source of slave labor for the Death Star project.
Vader's role in the Empire's triumph was eventually reported in a Holonet news broadcast, reaching as far as Tatooine. It was through this report that Obi-Wan Kenobi learned that Vader, whose real name was Anakin Skywalker, had survived their duel on Mustafar, contrary to his previous belief that he had died.
In the aftermath of the battle, half of the Delegation of 2000 withdrew their signatures from the Petition of 2000, fearing to continue challenging Palpatine.
Despite the Empire's victory, the Wookiees continued their resistance and provided refuge to Jedi. Approximately a year later, the fugitive Jedi Kento Marek sought refuge on Kashyyyk. Upon discovering Marek's location, the Empire launched a second invasion.