- "I mean, we're not talking Svivren here, but even Ukio should have taken them [the Galactic Empire] a little longer to overrun."
- ―Samuel Tomas Gillespee
In 9 ABY, Grand Admiral Thrawn attacked Svivren and several other worlds aligned to the New Republic. The Imperial Navy was opposed by the locals, the Svivreni species, who disliked very much the idea of being sieged. This caught the Imperials flat-footed. After several failed attempts against the Svivreni resistance, the Imperial Navy retreated, only to return later and try to occupy Svivren. For a long time, the Imperials were unsuccessful at fighting the local resistance, and their plight was well-known enough to have reached the ears of Samuel Tomas Gillespee, by then living at Ukio.
Eventually, after Thrawn's death in the Battle of Bilbringi, the Imperials retreated from Svivren. As a consequence of their fight, the Svivreni decided that their resolution was as good as a military-grade weapon, and decided to be even more determined about rejecting invaders.
- The Last Command Sourcebook
- The Thrawn Trilogy Sourcebook
- Geonosis and the Outer Rim Worlds
- The Essential Atlas