Korriban, known as Pesegam during the reign of Xim, was the sole planet in the Horuset system, located across the galaxy from Koros Major. It was the original homeworld of the Sith species and a sacred planet for the Sith Order, housing the tombs for many ancient and powerful Dark Lords of the Sith, and containing immense dark side power.
After the Hundred-Year Darkness, the remaining Dark Jedi interbred with the Sith species and ruled the Sith using their Force powers. After the Great Hyperspace War, Korriban was abandoned and became a barren world. It was the site of a Sith Academy, and became the headquarters of the One Sith.
It was close to Bosthirda and was located on the Nache Bhelfia and Kamat Krote hyperspace lanes.
This remote, forbidding planet was the original homeworld of the Sith species. At some point prior to 30,000 BBY a Killik colony was established on Korriban, which eventually produced a Killik Sith Lord. The insectoid colonists were swiftly driven off, though, by the Sith.
The Rakata invaded Korriban in an attempt to integrate the world into the Infinite Empire around 27,700 BBY, intending to harvest slaves from the planet to be used for Rakatan projects. The sole artifact to survive this era was the ancient Star Map, around which the tomb of Naga Sadow was later built.
The Rakata were eventually forced off the world after the Sith King Adas led his people against them. Adas died in the battle, and thus, despite this victory, the Sith society crumbled, and, in the ensuing centuries of strife, the Sith relocated to worlds such as Arbra, Ziost and Tund using captured Rakatan vessels, leaving Korriban as a graveyard world populated only by religious fanatics.
For a brief period, the world was at least nominally a member of Xim's empire and given the name Pesegam, from around 25,126 BBY until its fall.
The Sith Empire was founded in approximately 6,800 BBY by exiled fallen Jedi fleeing the Battle of Corbos, which concluded the Hundred-Year Darkness. The fallen Jedi landed on Korriban.
Using their training in the Force, the fallen Jedi amazed the Sith and elevated themselves to god-like status on Korriban, becoming the rulers of the Sith people. As years passed, and interbreeding occurred between the Fallen Jedi and the Sith, the term "Sith" came to mean not only the original inhabitants of Korriban, but also their fallen Jedi masters. Until the rise of Naga Sadow, the existence of the Sith Empire was unknown to the Galactic Republic.
Under the pall of Sith magic, this desolate world became more hellish and dangerous.The Sith Lords erected huge palaces and burial complexes to honor their fallen Dark Lords. Circa 5,000 BBY, the planet became an endpoint of the newly-formed Daragon Trail hyperspace lane, when it was discovered by Gav and Jori Daragon. This event triggered the Great Hyperspace War. After the fall of the Sith Empire, the planet lost much of its prominence in the galaxy, eventually falling off the galactic starcharts for a thousand years. Despite the belief the Sith as a species became extinct after the end of the war, isolated enclaves of Kissai and Massassi existed on the planet over a millennia after their empire's fall.