The world that gave the Cluster its name was one of its minor planets. Tion was largely covered by a world-spanning ocean and orbited two brilliant cyan stars. The planet was also orbited by three industrialized moons, with one of them hosting a spaceport.
One of the worlds of the Kingdom of Cron, Tion was absorbed into Xim's Empire. After the fall of the empire in 25,100 BBY, it would eventually join the Galactic Republic. After the empire collapsed, the planet would continue to thrive as a world of the Honorable Union of Desevro & Tion, eventually becoming part of the Tion Hegemony when the Tion Cluster joined the Republic.
- Geonosis and the Outer Rim Worlds (First mentioned)
- The Essential Atlas
- The Essential Guide to Warfare