The Imperial Invasion of Kashyyyk was the subjugation and enslavement of the world by the Galactic Empire, in 19 BBY. Lead by Moff Willhuff Tarkin and Darth Vader, the Battle was among the Empire's first demonstrations of it's might and power.
Following the devastation of Order 66 and the establishment of the Galactic Empire, Jedi Padawan and survivor Olee Starstone began looking for any Jedi survivors.
One destination she investigated was Kashyyyk, where Masters Yoda, Luminara Unduli, and Quinlan Vos had been stationed when Order 66 was carried out. She arrived on the planet along with several other Jedi survivors—Siadem Forte, Deran Nalual, Klossi Anno, Iwo Kulka, Jambe Lu, and Nam Poorf, as well as the slicer Filli Bitters. After meeting with Tarfful and Chewbacca, the Jedi learned of Yoda's survival. The Wookiees offered the band of Jedi safe harbor on Kashyyyk, but the meeting was interrupted by the arrival of a troop carrier at Kachirho.
Not long after the Jedi’s arrival, the Dark Lord of the Sith Darth Vader had arrived in the Kashyyyk system, along with the Imperator-class Star Destroyer Exactor, where it joined Moff Willhuff Tarkin and the Executrix. The two plotted their attack on Kashyyyk—Vader interested in hunting down and destroying the fugitive Jedi, Tarkin interested in enslaving the Wookiees for use in the construction of the first Death Star.
At around this time, the night before the main Imperial attack, Tarkin dispatched a platoon of stormtroopers under Captain Janzor to act as a distraction. Although all but three would be killed, due to a combination of a crash, unforeseen hostile fauna, and underestimating the Wookiees, they managed to distract the Wookiee forces long enough for the main Imperial thrust to conquer an entire continent.
Although the fleet commanders were eager to bombard the planet, Vader overruled them, ordering a direct assault on several cities including Kachirho, Rwookrrorro, Kepitenochan, Okikuti, and Chenachochan.
At Kachirho, the landed Imperial troops ordered the Wookiees to hand over the fugitive Jedi, but the enraged Wookiees instead attacked the troops, and Starstone and her Jedi soon joined the battle. As more Imperial forces landed, the Wookiee warriors and the Jedi covered the evacuation of Kachirho, as countless Wookiee civilians fled the Imperial troopers, fleeing from enslavement. Imperial AT-AT Walkers and gunships were engaged by jet catamarans, retrofitted with rocket launchers and other high-end military hardware, salvaged by the Wookiees from the remains of the earlier Battle of Kashyyyk. Realizing that the Empire was attacking indiscriminately, many traders and merchants onworld began to evacuate Wookiee families while others used their craft's concealed weapons to engage various imperial transports. By this time, all of the troopers of the first wave were dead.
A local hour after the attack had started, Lord Vader flew a Theta-class Imperial shuttle down to Kachirho, in an attempt to hunt the Jedi down. He was accompanied by Commander Appo and a squad of troops, but met heavy anti-air fire on his way down. Around the planet, the Imperial incursions were being repulsed by fierce Wookiee warriors, and an alarming number of Imperial troops (millions upon millions) were being lost in the assaults. Following Appo's advice, Vader acceded the fleet commanders the permission to begin orbital bombardment, warning them to save Kachirho for last.
Landing on a platform high up in Kachirho, Vader and his cadre of Stormtroopers disembarked and began fighting their way through the Wookiee warriors.
Confronting the Jedi
In order to prevent further Wookiee casualties, the Jedi revealed themselves. Olee Starstone had since broken off from Roan Shryne, who had since joined the Drunk Dancer, now leading a group of surviving Jedi they had located. Vader ordered the Stormtroopers to stay on the Wookiees, leaving the Jedi to him. Siadem Forte and Iwo Kulka quickly attacked Vader, attempting to unbalance him by using radically different lightsaber forms. However, Vader easily held them off, utilizing a combination of precision bladework and swift power attacks to put an end to their fancy twirling, putting his superior height and strength to good use to disrupt their momentum and sending them reeling. Vader decapitated the two Jedi, and then quickly "took care of" (killed) Jambe Lu, Nam Poorf and Klossi Anno.
Olee Starstone was suddenly alone against the Sith Lord. Starstone attempted to bring down Vader with a sudden offensive flurry, but realized that Vader was only allowing her to vent. Breaking off to reassess her strategy, she unwittingly allowed Vader to seize the offense. However, before he could finish Starstone, Vader's Stormtroopers were suddenly gunned down by a smuggler vessel that just appeared. Roan Shryne leapt off the Drunk Dancer, summoning Siadem Forte's lightsaber to his hand and killing Appo. Confronting Vader, Shryne provided Starstone and the other surviving Jedi with a chance to escape.
Shyrne vs Vader
As the two fought, Shryne managed to hold his own against Vader's relentless assault, actually scoring several hits. However, their battle was interrupted by the Imperial orbital bombardment.
As Shryne and Vader fought, the main battle began to drift east of the city, moving closer to the lake, as Imperial gunships, Walkers, and artillery drove the Wookiees down out of the city and towards the ground. Heading to the main Kachirho landing platform, Archyr and Starstone loaded their drop ship and transport with escaping Wookiees.
Abruptly, the Imperial gunships began to break off from Kachirho, as the orbiting Star Destroyers began their orbital bombardment. Shryne and Vader’s duel was interrupted by the strike, and the two moved inside one of the great wroshyr trees. Though they both survived, Vader's shuttle was destroyed by the flak. As they resumed their combat, Shryne deduced the weakness of Vader's suit to be the chest-mounted control-panel. His attempts to attack the panel forced Vader to adopt a defensive fighting method that left his limbs open, ultimately prompting him to resort to a telekinetic assault. Tearing apart the wooden ramps and platforms within Kachirho, Vader flung the debris at the hapless Jedi, battering him and knocking him off the platform on which they fought.
Fallen to a floor below, Shryne lay critically injured. Assured that Shryne was going to die anyway, Vader chose not to strike down the Jedi, instead revealing his true identity to the man—Anakin Skywalker.
As Shryne died, Imperial-class Star Destroyers began to descend into atmosphere, completing the conquest of Kashyyyk.
In the wake of the conquest, the Empire promptly enslaved the Wookiees. More then 200,000 Wookiee prisoners, including Tarfful, were moved to Imperial concentration camps in the Wawatt Peninsula. With the planet under Imperial control, Tarkin had gained valuable slave labor for the Death Star. In 3 BBY, the Empire would conduct a series of operations in the Kashyyyk forests which would bring hidden Wookiee natives into slavery.