The Battle of Kashyyyk, also known as the Battle of Kachirho, was a prolonged campaign against the Galactic Republic that took place during the Outer Rim Sieges and was among the final conflicts of the Clone Wars. It was fought on the planet Kashyyyk, the homeworld of the Wookiees that had been invaded by the Confederacy of Independent Systems hoping to claim the Kashyyyk hyperspace junction, as well as gain information on secret hyperspace routes rumored to be in Wookiee archives, that could turn the war in its favor. In the course of the battle, Supreme Chancellor Palpatine issued Order 66, clone troopers turned their weapons on their Jedi commanding officers, though the Wookiees helped many Jedi escape.
During the proclaimed transformation of the Republic into the Galactic Empire, confused fighting as part of an Imperial crackdown on the Wookiees followed.
Kashyyyk would be totally subjugated by the Empire several weeks later and endured a prolonged period of occupation until it was at last liberated by the New Republic in 4 ABY.
A climactic battle between the technologically advanced Empire and a race of primitive hairy aliens, the Wookiees, was present in George Lucas‘s original treatment for A New Hope. As the story changed and the trilogy structure was solidified in Lucas’ mind, the battle was postponed until Return of the Jedi, where it developed into a battle featuring Ewoks on the forest moon of Endor. At the same time, the Wookiees developed into a more technologically savvy, though not less hairy, species. Lucas’ original conception of the battle featured hundreds of Wookiees on screen. Due to costs, the original idea was scrapped and replaced by a battle featuring relatively few diminutive Ewoks, who did not play a very significant tactical role in the battle. A large-scale battle with hundreds of characters was eventually realized in The Phantom Menace.
The first depiction of this battle appeared in the 2004 video game Star Wars: Battlefront as the last level in the game’s Clone Wars Campaign. At the time of the game’s release, LucasArts did not want any Episode III content to be revealed very early, therefore the game’s depiction of the battle features clone troopers in phase I armor despite the fact that most clone troopers (besides the clone advisor in Republic Commando) would have already switched to phase II armor by the time this battle occurred.
The fight was parodied in LEGO‘s Revenge of the Brick spoof of Revenge of the Sith.
In LEGO Star Wars: The Video Game, an alliance of sorts between the clones and droids is depicted following the execution of Order 66. Needless to say, this event is not part of the Legends continuity.