The city was constructed in close orbit around the gas giant, and its builders hoped it would one day rival Cloud City in terms of both gas mining and popularity. Its inability to compete on these terms caused its citizens to gradually abandon it during the ferocious Clone Wars.
After the Imperial occupation of Cloud City, Tibannopolis lay almost completely uninhabited. Strangely enough, it was one of a relatively few colonies left operational when its mining operation failed to gain a profit.
Left to float aimlessly, the city was often plundered by inhabitants of other colonies whenever they found useful materials. What remained of the city sprawl became little more than a ghost town in the clouds.
Behind the scenes
In The Jedi Academy Sourcebook, Tibannopolis is repeatedly spelled "Tibannoplis."