Xerxes III (or Golumbin 699 III) was a planet located somewhere in the space of the galaxy's Alpha or Beta Quadrants, the third planet in orbit of the Golumbin 699 star system, at coordinates 2.29N 5.38W.
In the 23rd century, Xerxes was home to a Federation colony noted for mining programs. By reference stardate 2/2306.01, the world had a population of 1.2 million individuals of various races and cultures, chartered as a dependent colony of the Federation. (FASA RPG module: The Federation)
In the 24th century, Glav owned property on the planet that was not taken from him after he went bankrupt. Glav went to live there and discovered calvinum deposits after he began geological surveys. (DS9 novel: The Siege)