Approximately 2,000 star systems made up the cluster, which was named after Aitro Koornacht, a palace guard on Tamban who befriended the astronomer that first discovered it. Despite this high concentration of star systems with around 20,000 worlds, only a hundred or so planets bore life and only six produced sentient lifeforms. It was believed that seventeen planets outside the Duskhan League had lifeforms of some kind, but it was difficult to survey or contact them.
The Koornacht Cluster was known by the Fia as "The Great Multitude of the Circle of the Heavens" or simply "The Multitude", by the Wehttam as "God's Temple", by the Ka'aa as "No'aat Padu'll" or "The Little Nursery", by the Yevetha as "Home", and a number of other names.
The Crucible had operations in the Koornacht Cluster through the Sungrazer cooperative which operated in 3964 BBY. The Gladiator was one such vessel that operated in the region and was involved in a fight against Zayne Carrick.
During the Clone Wars, Obi-Wan Kenobi once traveled through the Cluster where he once encountered a bounty hunter using a lightwhip. At some point, the Yevetha began expanding from their spawnworld of N'zoth by using Aramadia-class thrustships with sublight capabilities, and used them to settle eleven worlds in the Koornacht Cluster.
Following the end of the conflict, the Galactic Empire established a presence in the region where they placed the core of their Black Sword Command in the Cluster with the directive of protecting the Core from attack. However, following the Battle of Endor, their base of operations around N'zoth was overrun by the Yevetha slave forces who managed to usurp the yards from the Imperial forces. Through the technology they had acquired, the Yevetha formed the Duskhan League and later were involved in the Black Fleet Crisis when they attempted to bring about their Great Purge of the region.
- Star Wars: Knights of the Old Republic: The Reaping
- The Cestus Deception (Mentioned only)
- Before the Storm (First appearance)
- Shield of Lies
- Tyrant's Test
- The New Rebellion (Mentioned only)
- The New Jedi Order: Agents of Chaos I: Hero's Trial (Mentioned only)
- The New Jedi Order: Agents of Chaos II: Jedi Eclipse (Mentioned only)
- The New Jedi Order: Force Heretic I: Remnant
- The New Jedi Order: The Unifying Force (Mentioned only)
- Millennium Falcon (Mentioned only)
- Star Wars Encyclopedia
- The Essential Guide to Planets and Moons
- The Essential Guide to Droids
- The Essential Chronology
- Alien Anthology
- Coruscant and the Core Worlds
- The Official Star Wars Fact File 7 (PLA1, PLA5, Planets of the Core Worlds)
- The New Essential Chronology
- Jedi vs. Sith: The Essential Guide to the Force
- The Complete Star Wars Encyclopedia
- Galaxy at War