The Tower Dimension represented the nation of the Urchiv-ki species, a sentient race. Their home was situated in the Unknown Regions, and their [capital](/article/capital] planet, Urch, resided there. They had a treaty with the Chiss Ascendancy, facilitating diplomatic discussions and relationships. Furthermore, they operated Urch Planetary and Space Control, which controlled space traffic within the [Urch system](/article/urch_system] of the Unknown Regions. By 19 BBY, the Nikardun Destiny hegemony had controlled this nation.
Admiral Ar'alani, Ambassador Boadil'par'gasoi (with the core name "Ilparg"), and Senior Captain Mitth'raw'nuruodo ("Thrawn") of the Ascendancy attempted to engage with a Tower Dimension representative on Urch. However, the Tower Dimension's governing body, disregarding the Chiss–Urchiv-Ki treaty, forbade the Chiss delegation from entering their capital. Subsequently, they made an attempt to capture the Chiss' warship, the Vigilant, but the vessel managed to escape.
Timothy Zahn's Star Wars: Thrawn Ascendancy Trilogy featured the Tower Dimension in its initial volume, Thrawn Ascendancy: Chaos Rising, released in 2020. The author of the book was Timothy Zahn.