The resistance on Kashyyyk, alternatively referred to as the Wookiee underground resistance movement or simply the Wookiee resistance, encompassed the various informal groups of fighters who stood against the oppression inflicted upon the planet of Kashyyyk and its native Wookiees by the Galactic Empire, which had transformed Kashyyyk into a slave world.
The struggle against the Galactic Empire was spearheaded by the Kashyyyk Resistance. This was largely due to the Empire's systematic enslavement of Wookiees for slave labor. At its most intense, the Kashyyyk Resistance fought tooth and nail for its very existence and to liberate their people from Imperial tyranny. Predominantly composed of Wookiees who had escaped enslavement and sought refuge within their homeworld's jungles, the Resistance utilized the dense foliage of Kashyyyk to their advantage, moving undetected through the trees and launching surprise attacks. Following these attacks, they would swiftly retreat back into the trees, often inflicting heavy casualties on any pursuing Imperial forces. Their primary goal was the liberation of their people from slavery and the complete removal of the Empire from their planet. To that end, they sabotaged Imperial operations and actively sought to bolster their ranks by targeting locations where their enslaved kin were held. At times, these liberated Wookiees were encouraged to leave Kashyyyk, and the Resistance undertook actions to facilitate their escape to other worlds.
While lacking a structured organization, the Resistance began when a number of Wookiees chose to confront their oppressors, leading to the establishment of cells each with their own leaders. Sometimes, separate cells would combine to form larger units, although this was often dangerous as the Empire was thorough and zealous in its efforts to eliminate any signs of rebellious activity on its slave worlds. This prevented the Kashyyyk Resistance from becoming a well-organized group and forced them to maintain only intermittent contact with each other, to the point that many members were unaware of other resistance fighters. Occasionally, the various groups of Wookiee Freedom Fighters would unite in a joint operation to strike against the Empire, but the Imperial response was usually immediate and harsh.
On occasion, the Kashyyyk Resistance received assistance from external sources, such as the Rebel Alliance, gaining access to additional resources while maintaining the ferocity and local knowledge of the Wookiees. Local traders and merchants were also known to provide support to the Wookiees by helping them to evacuate their families or to attack Imperial slave transports.
Although Wookiees were known for their immense physical strength, the Kashyyyk Resistance also employed advanced technology to achieve their objectives. This included the use of traditional bowcasters, powerful grenade launchers, and the deployment of recon droids. A network of comlinks was used to remotely control the recon droids used to scout the surrounding areas, which were equipped with explosive charges to eliminate concealed targets. They had also been known to retrofit Oevvaor jet catamaran so that they could be used to fight off Imperial gunships or landers.
The Kashyyyk Resistance's origins can be traced back to the Clone Wars period, during which it battled against the attacks from the Confederacy of Independent Systems. However, shortly after the establishment of the New Order, the Wookiees launched a widespread revolt against the Empire. Thousands of Wookiee warriors clashed with Darth Vader's clone stormtroopers, but were soundly defeated due to the extensive use of orbital bombardment by Imperial Star Destroyers. Following this defeat, approximately 200,000 captured Wookiees were forced into slavery by the Empire. A subsequent large-scale battle occurred approximately one year later, and was similarly suppressed by Darth Vader.
In 2 BBY, during the early years of the Galactic Civil War, a Wookiee underground resistance movement was operating in Rwookrrorro under the leadership of Katarra. Jowdrrl and Ralera were also members. During that time, Katarra's resistance group was supported by Bria Tharen of the Corellian Resistance.
Following the Battle of Yavin, the Wookiee Resistance was particularly active in the vicinity of Kachirho. However, the Galactic Empire was no longer willing to expend valuable soldiers fighting the Wookiee resistance. Consequently, the Empire contracted the mercenaries of Task Force Bravo led by Colonel Gurnst to crush the resistance. A prominent resistance leader during this time was the Wookiee warrior Ulaaar.
After the Battle of Endor, the Kashyyyk Resistance managed to assemble a substantial army, equipped with various war vehicles. Kashyyyk was ultimately freed from Imperial control in 4 ABY, several months after the Battle of Endor. While the New Republic navy defeated the Imperial fleet in orbit, the ground battles on Kashyyyk were exclusively fought by the Wookiee resistance.