An assault was carried out on an Imperial outpost circa 14 BBY during the Imperial Era. This attack was instigated by the local resistance movement on the planet Kashyyyk, as a direct response to the Galactic Empire's occupation of their home world. As a result of this offensive, the Wookiee Commander named Choyyssyk was apprehended and subsequently imprisoned within the Imperial Refinery located on Kashyyyk. Following a period of imprisonment lasting months, in the year 14 BBY, Choyyssyk's liberation was achieved through the combined efforts of Cal Kestis, a fugitive Jedi Padawan, and the Partisans, an insurgent organization under the command of Saw Gerrera, a militant advocate for freedom.
Following the victory of the Kashyyyk resistance and the Partisans over the Imperial forces, Mari Kosan, a member of the Partisans, brought up the subject of Choyyssyk's capture during the aforementioned attack in conversation with Kestis.
The 2019 video game Star Wars Jedi: Fallen Order, created by Respawn Entertainment, included a reference to the assault on the Imperial outpost.