- "Separatists have sympathizers in every village."
- ―A Republic supporter referring to the Ord Mantell Separatists
After the Treaty of Coruscant, many planets seceded from the Galactic Republic to join the Sith Empire or pursue independence. The corrupt planetary government of Ord Mantell opted to remain loyal to the Republic. However many on the planet desired the independence of their world. The resulting separatist movement sparked a civil war on the planet, with the government receiving backing from both the Republic and elements of the criminal underworld.
The Ord Mantell separatists established a network of underground bases from which they launched guerrilla attacks on the Ord Mantell government and Republic targets. The attacks resulted in the destruction of the Ord Mantell landscape and the destabilization of the local governments. A primary base of the separatists was a large volcano. Located on the island of Avilatan, the heart of the volcano was a Separatist Stronghold used to conduct meetings and organize separatist forces. Separatist leaders often met in the stronghold. Another major base was the island of Mannett Point. After invading the island, Separatist forces captured large amounts of Republic munitions, and used it against government and Republic forces. Such munitions captured included small arms and rocket launchers.
The Separatist movement held large portions of the island of Avilatan. Separatist forces fought for control of several villages on the island, including Drelliad and Talloran villages. In addition, the Avilatan Badlands were a hotly contested area. Separatist forces claimed much control of the Badlands, and led raids against Republic convoys. The Separatists used the Badlands as an ambush point, planting bombs along it.
- "After separatist forces were crushed on Ord Mantell, Governor Chornarov secretly offered their leaders and surviving troops asylum on Cademimu."
- ―Satele Shan
Investigation into the the separatist movement's roots revealed that it shared financial backing with the Justicars' Brigade paramilitary group—the backers being the Sith Empire. The Sith Empire contributed propaganda, munitions, and financial aid to the Separatist cause. The Sith Empire also maintained a Listening Post on Ord Mantell. It provided intelligence on Republic movements to the Separatists.
At the end of the civil war, a portion of separatists led by General Ortol moved to Cademimu V. Cademimu governor Chornarov declared independence of the Republic, while Ortol and his men helped him take control of the planet and its missile defenses. The action was met with resistance from Cademimu's population. When the Republic and Empire intervened, most of the separatists were killed along with their commander, General Ortol.
- The Old Republic—The Lost Suns 1 (First mentioned)
- Star Wars: The Old Republic
- Star Wars: The Old Republic: Galactic Strongholds (Mentioned only)
- (First identified as Mantellian Separatist Movement)
- The Art and Making of Star Wars: The Old Republic
- Star Wars: The Old Republic Explorer's Guide
- Star Wars: The Old Republic Encyclopedia
- Mask of the Pirate Queen