- "It's a system we cannot afford to lose."
- ―Obi-Wan Kenobi
The solar system contained the inhabited worlds of Kashyyyk, home of the Wookiees, and Trandosha, home of the Trandoshans. It also contained the Wookiee colony moon of Alaris Prime, orbiting the gas giant Alaris, as well as the Trandoshan moon of Wasskah, where Trandoshans hunted various species captured around the galaxy for sport. The Trandoshans knew it as the Hsskassi system, but the wider galaxy would call it the Kassyyyk system when the Wookiees became its first, and sole, representatives in the Republic Senate. The system was relatively isolated as it was far from the central trade routes, although it was located close to a major route for the southwestern quadrant, and was home to an important Republic navigation and communication relay station.
During the beginning of the Jedi Civil War, Kashyyyk was controlled by Czerka Corporation, who had struck a deal with the corrupt Wookiee chieftain Chuundar and enslaved the Wookiee population to run an illegal slave-trade operation out of the planet. The amnesiac Revan, aided by his Wookiee life-debtor and brother of Chuundar, Zaalbar, overthrew Chuundar and incited the planet-wide Rebellion on Kashyyyk, forcing Czerka to abandon their slave-trade operation and leave the system.
The Wookiees and Trandoshans of the system were locked in a bitter rivalry for centuries. During the waning days of the Republic, this became a pressure point when debate arose over which planet's representative would be chosen as the system's Senator in the Galactic Senate.
- Star Wars: The Old Republic (Mentioned only)
- Star Wars: Galactic Battlegrounds
- Star Wars: Galactic Battlegrounds: Clone Campaigns
- Star Wars: Battlefront
- Star Wars: Republic Commando
- Star Wars Adventures 4: Jango Fett vs. the Razor Eaters
- Star Wars: The Clone Wars game
- Star Wars: Battlefront II
- Star Wars: The Clone Wars – "Padawan Lost"
- Star Wars: The Clone Wars – "Wookiee Hunt"
- Order 66: A Republic Commando Novel
- Star Wars: Episode III Revenge of the Sith
- Star Wars Episode III: Revenge of the Sith junior novel
- Dark Lord: The Rise of Darth Vader
- Star Wars: Empire at War
- Star Wars: Empire at War: Forces of Corruption
- The Star Wars Holiday Special (First appearance)
- Star Wars Galaxies: Rage of the Wookiees
- The New Jedi Order: Destiny's Way
- Legacy of the Force: Inferno
- LEGO Star Wars: The Video Game
- LEGO Star Wars: The Complete Saga
- Star Wars Battlefront: Elite Squadron
- LEGO Star Wars: Revenge of the Brick
- Star Wars Battlefront: Renegade Squadron
- The Essential Guide to Planets and Moons
- Star Wars: Empire at War: Prima Official Game Guide
- Star Wars: Empire at War: Forces of Corruption: Prima Official Game Guide
- The Essential Atlas
- Star Wars: Edge of the Empire Core Rulebook