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, 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", and a number of other names.
The Crucible had operations in the Koornacht Cluster through the Sungrazer cooperative which operated in 3,964 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 travelled 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 thrustship that only had sublight capabilities and used them to settle twelve 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 Cluster with the task 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.