Csilla was a frozen planet located in the Unknown Regions. It was home to the, Chiss, race.
Locked in an ice age for millennia, Csilla forced many socioeconomic and technological changes upon the Chiss, but few physical changes. Contrary to beliefs in a link between the Chiss skin color and the Csillan temperature, scientists concluded that the Chiss’ blue skin was caused by a mineral found in the Csillan hydrosphere.
Csilla was the capital of the Chiss Ascendancy. It was also home to the Expeditionary Library. Grand Admiral Thrawn was born here.