Illarh was a planet located somewhere in the galaxy's Alpha or Beta Quadrants, situated near Federation territory.
History and specifics[]
Illarh was the home of the Illarhi civilization.
In the year 2373, Illarh was conquered without resistance by Dominion forces under the command of the Vorta Sejeel because of its proximity to Federation space. (STA - Tales of the Dominion War short story: "What Dreams May Come")