The Enslavement of Qu'onos was the enslavement campaign against Qu'onos, the homeworld of the Klingons, launched by the Galactic Empire in 19 BBY.
The newly-established Galactic Empire, after the end of the Clone Wars, was exerting it's power and control over the numerous regions of the Universe. The Imperial war machine was rapidly expanding and growing, and needed new labor and natural resources. The Death Star construction project needed labor, natural resources, and components. As a result, Emperor Palpatine authorized Grand Moff Willhuff Tarkin, commander of the Death Star construction project and one of the Empire's primary officials, to conduct a series of campaigns to bring slave labor, natural resources, and scientific laboratories under the Empire's control. The Klingons of Qu'onos, like the Mon Calamari and Quarren of Mon Calamari, the Wookiees of Kashyyyk, and the Vulcans of Vulcan, were considered ideal slave labor. The Klingons, although respected members of the Empire (and the Republic beforehand), would be targeted for enslavement.
A fleet of 50 Star Destroyers and hundreds of transports and support vessels, commanded by Tarkin, appeared in orbit over Qu'onos. The Imperials ordered the planet to stand down, to prepare for landings by Imperial troops. The Klingons, however, refused, labeling it a "heinous" violation of their rights as sovereign members of the Imperial Senate. The Imperial fleet then began it's operations. The Klingons however had a defense force, which they had been permitted to maintain under the Local Command Act of 20 BBY, passed during the Clone Wars. The Imperial Star Destroyers quickly destroyed the Klingon force, although losing 8 of their numbers. Afterwards, Imperial spies inserted on the planet switched off Qu'onos planetary shield generators, and immediately, transports landed on the world, carrying millions of stormtroopers and thousands of Walkers and assault vehicles. The Imperials assaulted the planet's primary cities, including First City, Qam-Chee, and Tong Vey. The Klingon warriors put up heavy resistance however, and the Imperials paid dearly for every square mile of land captured.
Eventually, however, the overwhelming numbers of the Imperial invasion force and the more advanced technology overwhelmed the Klingons, and the Klingon High Council was forced to surrender.
The Empire immediately enslaved the Klingons, using the service of Transdoshan mercenary enslavers. More then 500,000 Klingons were moved to containment camps within the Hamar Mountains. Klingon slaves were shipped off world to work on the Death Star and other Imperial construction projects. The Empire also established a mining facility on Praxis, Qu'onos' mineral rich moon. Klingon slaves were forced to work at this installation as well, as also at mining facilities on the world. The Empire also constructed a orbital defense base over the world.