After the conclusion of the New Sith Wars in 1000 BBY, the planet was involved in the Belderone Contention with the Galactic Republic. The Republic's Judicial Forces brought the conflict to a violent end at the Battle of Dandrian's Ring.
The Confederacy of Independent Systems tried to conquer the planet shortly before the Battle of Coruscant to act as a fortress for the Separatist Council, but were thwarted by Galactic Republic forces led by Obi-Wan Kenobi and Anakin Skywalker. General Grievous's flagship, the Invisible Hand, did, however, manage to kill twenty-seven Jedi Knights attempting to evacuate the populace of Belderone, among them Flint Torul and thousands of civilians aboard the evacuation ships. The Separatist Council fled to Utapau instead. Belderone was the homeworld of Flint, the son of a Jedi Knight killed in the battle.
Kuat Drive Yards later assembled AT-ATs on the planet, which the Galactic Empire used to destroy Flint's hometown. The death of Flint's mother led to him being seduced to the dark side of the Force by Darth Vader and later becoming the Dark Lord of Belderone, apprenticed to Lumiya. Many refugees from Belderone fled to nearby Naldar, but that world was conquered after the Battle of Endor by Imperial Remnant forces led by Flint himself. However, Luke Skywalker managed to redeem Flint. Flint returned to Belderone to help his people rebuild.
Belderone and Kulthis both had Stenax colonies. The reason the Stenaxes colonized these planets is unknown. They remained isolated from the other inhabitants, on Belderone settling a previously uninhabited continent. Thankfully, they did not participate in the Stenax Massacres.
After the defeat of Waru and the destruction of the star Crseih, the New Republic sought to relocate the homeless Firrerreos, whose homeworld had been desolated by the Galactic Empire. The Firrerreos had been placed in suspended animation in slaveship by the Empire. Flint persuaded the Belderonians to accept the Firrerreos on Belderone. However, rivalry between the two peoples arose. The Yuuzhan Vong used this rivalry to their own ends, setting the Firrerreo and Belderonians against each other. Belderone, weakened by internal conflict, was then easily conquered by the Yuuzhan Vong, who enslaved the Belderonians and rendered the Firrerreo all but extinct.
- Labyrinth of Evil
- Reversal of Fortune (Mentioned only)
- Star Wars Annual 3: The Apprentice (First appearance)
- Star Wars 92: The Dream (Mentioned only)
- The New Jedi Order: Force Heretic I: Remnant (Mentioned only)
- The New Jedi Order: Force Heretic III: Reunion (Mentioned only)
- Millennium Falcon (Mentioned only)
- The Essential Guide to Vehicles and Vessels
- "ComicScan: Paint Him Black"—Star Wars Galaxy Magazine 11
- "ComicScan: 20 Tales to Tantalize"—Star Wars Galaxy Collector 5
- The Essential Guide to Alien Species
- The New Essential Chronology
- "Unknown Soldier: The Story of General Grievous"—Star Wars Insider 86
- Evil Never Dies: The Sith Dynasties
- The Complete Star Wars Encyclopedia
- The Essential Atlas
- The Essential Reader's Companion
- Star Wars: Edge of the Empire Core Rulebook