Territory G5-623, also referenced as Imperial territory G5-623 or simply G5-623, designated an Imperial-controlled zone. This territory encompassed the Mid Rim planet of Kashyyyk, which was under occupation. The Wookiee inhabitants of Kashyyyk were subjected to slavery through the use of behavioral modification biochips. Following the Battle of Endor, it evolved into an isolated Imperial remnant, maintaining its autonomy from the wider Empire. The existence of Imperial territory G5-623 concluded with the Liberation of Kashyyyk by the New Republic in 5 ABY.
During the Age of the Empire, the Galactic Empire launched an invasion of Kashyyyk and subsequently enslaved the Wookiee population. In the aftermath of the Battle of Endor, Imperial territory G5-623 transformed into a self-governing and isolated Imperial remnant. This remnant was under the leadership of Grand Moff Lozen Tolruck, who maintained control over the Wookiees using inhibitor chips. Similar to Governor Ubrik Adelhard, who governed another Imperial remnant within the Anoat sector, Tolruck perpetuated the false narrative that Emperor Palpatine had survived the destruction of the second Death Star. Tolruck's remnant operated independently, not aligning with the Imperial forces under the command of Grand Admiral Rae Sloane and Fleet Admiral Gallius Rax.
As the demand for Wookiee slaves decreased, Tolruck and Commandant Theodane Sardo considered the possibility of farming the Wookiee population for meat production. However, in 5 ABY, Tolruck and his Imperial forces were defeated during a mass uprising sparked by the actions of Han Solo, Chewbacca, and Sinjir Rath Velus. The remaining Imperial forces surrendered when New Republic forces led by Admiral Gial Ackbar, Princess Leia Organa, and Captain Wedge Antilles successfully liberated the system. Subsequently, Wookiee and New Republic forces conducted operations to eliminate remaining Imperial resistance on Kashyyyk, including the camp led by Commandant Dessard.