The Unknown Regions, also referred to as Unknown Space, the Unknown Territories, the Unknowns, and the Outer Reaches, was a region of the galaxy located in the galactic west beyond the Outer Rim. Largely unexplored throughout galactic history, it remained a mystery to space travelers and served as a source of tales and wonders.
To those who lived in the Unknown Regions, it was known as the Chaos. They knew the rest of the galaxy as «Lesser Space.» The Chaos was a very dangerous place to navigate due to supernovae, black holes, gravity wells, and stranger phenomena. These hazards made navigation computers unreliable within the Chaos, and were the source of the name «Chaos.» Due to such hazards, the peoples of the Unknown Regions employed Force-sensitive navigators, individuals endowed with the Force power of precognition, to navigate. When navigators were unavailable, long hyperspace journeys had to be jump-by-jump instead.
According to the legends of the Chiss Ascendancy, the Unknown Regions had not always been the collection of constantly-shifting pathways and twisted hyperspace routes that it was by the Republic Era. The legends claimed that, at the beginning of space travel, traveling between the stars of the region was as easy as regular travel, but, thousands of years prior to 19 BBY, a series of chained supernovas threw huge masses at near-lightspeed between the stars, demolishing asteroids, devastating entire planets, or even setting off more supernova explosions. The movement of these masses, combined with heavy electromagnetic flux in a number of regions, brought about the ever-changing hyperlanes that still plagued travel efforts a thousand years later.
Dating as far back as the Old Republic, the Jedi Order was known to utilize the planet Ilum as a source of kyber crystals, which were important in the construction of a Jedi‘s lightsaber. At a young age, Jedi younglings were sent to Ilum to retrieve these crystals, traveling into the Unknown Regions aboard a ship known as the Crucible.
Eventually, the Chiss Ascendancy rose to become a major power in the Unknown Regions. This empire recognized that the instability of the Unknown Regions could be an advantage because, if the Unknown Regions limited travel, the chances at an enemy faction launching an invasion were also limited. However, Chiss intelligence and recon missions were also slowed by the region’s instability, blinding them to potential hidden foes who sought to bring destruction and conquest to their domain. Furthermore, the Chiss had a strongly ingrained policy against initiating hostilities, and were only allowed to use their military for defense purposes.