The Tower Dimension was the nation of the Urchiv-ki sentient species, based in the Unknown Regions where its capital, the planet Urch, was located. It had a treaty with the Chiss Ascendancy that allowed diplomatic meetings and relations. It also maintained Urch Planetary and Space Control, which controlled space traffic in the Urch system of the Unknown Regions. In 19 BBY, the nation was controlled by the Nikardun Destiny hegemony.
When the Ascendancy's Ambassador Boadil'par'gasoi, core name "Ilparg," Admiral Ar'alani, and Senior Captain Mitth'raw'nuruodo "Thrawn" attempted to speak with a Tower Dimension representative at Urch, however, the nation's government prohibited them from visiting their capital, ignoring the Chiss–Urchiv-Ki treaty. The government then tried to capture the Chiss' warship, the Vigilant, but it escaped.
The Tower Dimension was mentioned in the 2020 novel Thrawn Ascendancy: Chaos Rising, the first volume of the Star Wars: Thrawn Ascendancy Trilogy by author Timothy Zahn.
The Tower Dimension was first mentioned in the 2020 novel Thrawn Ascendancy: Chaos Rising, the first volume of the Star Wars: Thrawn Ascendancy Trilogy by author Timothy Zahn.