- "Ooookay, so it's a big, dead, important rock."
- ―Kyle Katarn
Around 4,000 BBY Viscountess Mireya of Vjun married into the Tapani nobility by wedding High Lord Tritum XI of House Mecetti. Mireya brought with her Sith teachings that corrupted the House's protector organization, the Mecrosa Order, turning it into a Sith cult.
Vjun was the homeworld of the Malreaux family, one of the oldest and wealthiest on the planet. The Viscount Malreaux performed experiments on midi-chlorians that drove the populace of Vjun insane, leading to their murder of each other in 29 BBY. One of the few survivors was the Viscountess Whirry Malreaux, whom gave her son, Whie Malreaux, to the Jedi Order so he could escape the horrors of his birthworld. Whirry remained on Vjun with her Force familiar, the Vjun fox Miss Vix. Droids such as the FIII Footman Droid and the R2-series were used as the workhorses of the Vjun population as they were rather more resilient to the highly acidic climate.
In 20 BBY, Château Malreaux served as a hideout for Count Dooku in the Clone Wars. He took an old woman's house and invited Jedi Master Yoda to come and save him from the dark side. In reality, Dooku had hoped to use the power of the dark side to destroy his former master. This failed when Jedi Master Obi-Wan Kenobi and Anakin Skywalker showed up and Dooku suspected treachery.
The planet later served as the headquarters of dark-side Executor Sedriss and Emperor Palpatine's elite forces of Dark Jedi. Before this, it was where Darth Vader's personal fortress, Bast Castle, resided. It had concentrated acid rain and the fortress was well guarded by many of Vader's best troops, including the legendary Dark Troopers.
Kam Solusar trained as a Dark Side Elite on Vjun before Luke Skywalker turned him to the light-side on Nespis VIII, six years after the Battle of Endor. Soon after, three Ysanna prisoners from Ossus were taken to Vjun to serve as raw material for creating new clone bodies of Emperor Palpatine. The Ysanna were frozen in carbonite to await the future construction of a clone laboratory within Bast Castle. However, Luke Skywalker and his Jedi trainees stormed the castle to defeat the Emperor's minions.
Kyle Katarn and Jaden Korr visited Bast Castle in order to stop the cult known as the Disciples of Ragnos from draining the force energy there. They soon found that Kyle Katarn's missing pupil, Rosh Penin, had been turned to the dark side and was stealing the energy himself. After a battle with Jaden Korr, Desann's former apprentice,Tavion Axmis, eventually came forth as the leader of the Disciples of Ragnos. Unfortunately, she escaped with Rosh.
Later, in 22 ABY, the Jedi historian Tionne Solusar discovered that Obi-Wan Kenobi's lightsaber had been recovered by Vader and stored at Bast Castle. Since an information broker had sold this information to them, she feared that others may have gotten to it first. Thinking it was just a simple trip and time for training, Tionne allowed Anakin Solo, Tahiri Veila, Uldir Lochett, and Ikrit to accompany her. They left on her Jemlaat-class yacht Lore Seeker.
Having arrived at Bast Castle, they discovered another vessel and feared another group had reached it first. Tionne also discovered hssiss on Vjun, just like those on Ambria, suggesting the creatures had been bred on both worlds by the ancient Sith. Having survived the fortress's automated defense systems and booby traps, they discovered the lightsaber in a protected alcove. Unfortunately, a group of mercenaries and pirates under a cloaked man named Orloc arrived. Orloc wielded a lightsaber and claimed to be a mage who possessed great powers. His henchmen also stole Kenobi's lightsaber.
In response, the Jedi pursued Orloc and his henchmen on a chase through Bast Castle. During a confrontation, Orloc easily defeated Ikrit in lightsaber combat since the Kushiban had no lightsaber at all. He also deceived Uldir by claiming to train him all the Force skills he desired. However, the other Jedi managed to rescue Uldir and escape Bast Castle, along with Kenobi's lightsaber and the holocron of the ancient Jedi Master Asli Krimsan.
Behind the scenes
- Yoda: Dark Rendezvous
- Labyrinth of Evil (Mentioned only)
- Star Wars Episode III: Revenge of the Sith novel (Mentioned only)
- The Rise and Fall of Darth Vader
- Star Wars: Rebellion
- Dark Empire II (First appearance)
- Empire's End
- Star Wars: Jedi Knight: Jedi Academy
- Junior Jedi Knights: Vader's Fortress
- Junior Jedi Knights: Kenobi's Blade (Mentioned only)
- The Essential Guide to Alien Species
- Revenge of the Sith: The Visual Dictionary
- Star Wars: The Complete Visual Dictionary
- Evil Never Dies: The Sith Dynasties
- The New Essential Chronology
- "Order 66: Destroy All Jedi"—Star Wars Insider 87