Ruusan's mineral deposits proved disappointing but it was the only source for the Ruusan crystal.
Ruusan had three moons, referred to by locals as the "Three Sisters." Smugglers claimed that at least one of the moons had ruins of an ancient civilization.
The planet was first colonized between 15,000 BBY to 8000 BBY, sometime between the Kymoodon Era and Rianitus Period. In 2200 BBY Ruusan was one of the ore-rich planets of the Teraab sector claimed by the Mining Guild, until the planet proved disappointing. All that remained on the planet were few optimistic claim jumpers and fugitives.
Ruusan was the site of seven battles between the Sith's Brotherhood of Darkness and the Jedi's Army of Light. During the last battle of Ruusan (1000 BBY) between the Jedi under Lord Hoth, and the Sith under Lord Skere Kaan, much of the planet's surface, including vegetation and several cities, were destroyed.
After the battle had ended, a Jedi Knight named Johun Othone petitioned the Galactic Senate to construct a grand mausoleum containing the one-hundred fallen warriors called The Valley of the Jedi, located on the former location of Olmondo.
Despite this, the expanding nebulae of the sector erased the hyperlanes connecting Ruusan and the world was quickly forgotten, as the Galactic Republic turned inward. Isolation and crossbreeding amongst the inhabitants produced a near-Human population that became known as Ruusanians. Shifting nebulae within the stellar nursery of the Teraab soon erased hyperspace routes to Ruusan, leaving it inaccessible from the galaxy at large. The Separatists briefly established a spy post over one of Ruusan's moons during the Clone Wars, but it was soon destroyed. By the time of the Galactic Empire's reign, Ruusan was mostly forgotten.
Rediscovered by the smuggler Jerg in 11 BBY, the planet came to be used by independent spacers and merchants as a base of operations. A decade later, Rebel refugees from Sulon settled on the planet, following Jerg and Morgan Katarn.
The planet's isolation would end shortly after the Battle of Endor. The Dark Jedi Jerec, informed of the location of the Valley of the Jedi, came to the planet intending to claim the Valley's power for himself. The Jedi Kyle Katarn, assisted by the spirit of Qu Rahn, managed to stop Jerec, slaying the Dark Jedi below the monuments that Othone had built centuries ago.
Katarn would return to Ruusan in 12 ABY to reestablish his connection to the Force, during the confrontation of the Empire Reborn, and in 14 ABY, during the Disciples of Ragnos crisis to investigate the Valley of the Jedi for cult activity.
The world was later targeted by the Yuuzhan Vong, who successfully invaded and occupied the planet over a year into their invasion of the galaxy. It would remain under Vong control until the end of the war.