The Sardaukar are the emperor's fanatical soldiers in Frank Herbert's Dune. Shaddam IV of House Corrino relies on them as the elite military force that protects imperial power and suppresses rebellion.
The Sardaukar are feared throughout the Imperium because their brutal training produces exceptionally disciplined and capable fighters. Their reputation is so strong that even powerful Great Houses hesitate to challenge the emperor openly. They often wear distinctive uniforms and operate as the emperor's personal troops, although they can be deployed in major political and military conflicts.
A common mix-up is confusing the Sardaukar with the Fremen. The Fremen are the desert people of Arrakis, while the Sardaukar serve the emperor. The Harkonnens are a rival noble House, and the robot army is not the imperial force described in the novel. Herbert later reveals that the Sardaukar's military excellence is connected to the harsh prison planet Salusa Secundus, where many are recruited and trained.