After the Xim Wars and the death of Xim, the Hutts raided the Kiirium Reaches bordering Hutt Space for slaves, but otherwise left the worlds alone. This changed when the Galactic Republic blazed the Perlemian Trade Route and encountered the Tionese. The Hutts feared that the Humans would unite and overrun them, and decided to take preemptive action. They attacked the worlds of the Kiirium Worlds and wiped out every last man, woman, and child they encountered. The Hutts destroyed the colonies, irradiating the worlds and erasing their histories. They destroyed or towed away the Hyperspace beacons that Xim had built, leaving only the Warrior's Trace as a possible invasion corridor to the Tion Cluster.
The Kiirium Reaches were completely depopulated by the invasion, reduced to barren, radioactive worlds with very few hyperlanes in the region. Over time, they became known as the Ash Worlds.
The Tionese later remembered, in a largely garbled form, the Devouring as a winter religious holiday, with different traditions on various worlds. Some traditions, such as those of Stalimur, had a night of silent confession and burning candles to ward away evil spirits, while others, such as the Wakemeet festival on the planet Barseg, had children dress up as evil spirits, and would receive candy from their elders in exchange for a year's blessing.
The destruction of the Kiirium Reaches was so comprehensive that knowledge of their very location was lost for millennia. Indeed, until the time of the early Galactic Civil War, Ximologists had not connected the Ash Worlds to the Devouring, and instead believed that some kind of astronomical event like a supernova had been the cause of the devastation there (though evidence of such an event had never been found). The expeditions of Bleys Harand and Henrietya Antilles largely solved the puzzle of the Ash Worlds, with discoveries such as the Antilles Map conclusively identifying devastated worlds in the region with the lost thrones of Xim's empire.