The Kiirium Reaches were settled by Humans in ages before the rise of Xer VIII in the Tion Cluster. Xim the Despot quickly expanded his empire into these worlds between 25,120 and 25,096 BBY. The region was dubbed the Kiirium Reaches, and the lush planets Huronom and Astigone became the Seventh and Eighth Thrones of the empire.
After the defeat of Xim, the Hutts made the Kiirium Reaches a buffer between the Hutt Empire and the Tion Cluster, regularly raiding it for slaves. After the Tionese made contact with the Galactic Republic in 24,500 BBY, however, the Hutts saw this as the prelude to an alliance against them. Taking pre-emptive action, the Hutts exterminated the Tionese to the last man, woman, and child within the old borders of the Kiirium Reaches in a genocidal campaign known as the Devouring. Their settlements were vaporized, their worlds bombarded and poisoned, their histories, and eventually even their names erased. The planet's name were lost and most were renamed. Xim's hyperspace beacons were destroyed or towed away for the Hutts' own purposes, leaving future explorers to find new routes through the desolation. Only the beacons and a few Tionese worlds along the Salin Corridor (known at this time as Warriors' Trace) were spared to preserve a potential Hutt invasion corridor to the Tion and make sure there were hostages to take along the way. The location of the historical Kiirium Reaches was lost and was the subject of much debate among scholars for millennia. The locations of Huronom and Astigone were forgotten, and they became known as the Lost Thrones of Xim. Columex and Trogan were popular suggestions for the location of Huronom, and numerous luxury resorts on Centares bore the name Astigone to claim the title of the Eighth Throne. Farther afield, the likes of Jabiim, Lucazec and even Lantillies were proposed as Lost Thrones.
This region of thousands of barren worlds still bearing the invisible scars of radiation was finally called the Ash Worlds, a name so widely known that the Republic adopted it for that sector of space. The spared Kiirium star systems along the Salin Corridor were not included in the Ash Worlds. Astronomers had scoured the area searching for the remnants of a supernova or some other devastating natural event, but nothing had ever been found.
The Devouring was remembered in a garbled fashion on many worlds of the Tion Cluster as a winter holiday. For some worlds such as Stalimur, the holiday was a time for pious reflection, and the day even took the name "the Devouring". On other worlds it was a more light-hearted festival, such as the Wakemeet of Barseg.
After 19 BBY, the Galactic Empire interdicted many of the Ash Worlds for weapons research. However, this did not discourage the historian Bleys Harand, who made numerous secret expeditions into the Ash Worlds. Harand and his students, including his protégé Henrietya Antilles, explored the Ash Worlds and reported that the radiation levels on numerous planets fit the profile of fission bomb attacks some twenty-five thousand years earlier. With the Hutt Empire known to have conducted similar actions, Harand argued that the Ash Worlds were a remnant of the Kiirium Reaches, and that the Devouring holiday was a memory of a genocidal campaign waged by the Hutts against the Tionese.
Further explorations into the Tion Cluster led to Henrietya Antilles' discovery of the Great Duinarbulon Mausoleum, which contained a large number of ancient records. After deciphering one of them, the Antilles Map, Harand was proved correct: the Map showed that the hostile world of Wyndigal 2 was once Huronom, while the anonymous OHS3842-03 had been Astigone.