The Devouring refers to a campaign orchestrated by the Hutts, which involved the extermination of the Tionese settlements within the Kiirium Reaches.
Following the Xim Wars and the death of Xim, the Hutts initially contented themselves with raiding the Kiirium Reaches, which bordered Hutt Space, for slaves. However, they generally left the worlds themselves untouched. This situation dramatically shifted when the Galactic Republic established the Perlemian Trade Route and encountered the Tionese. Fearing that the Humans might unify and pose an existential threat, the Hutts opted for a preemptive strike. They launched an all-out assault on the Kiirium Worlds, systematically annihilating every man, woman, and child they encountered. The Hutts eradicated the colonies, rendering the planets radioactive and obliterating their historical records. They either destroyed or relocated the Hyperspace beacons constructed by Xim, leaving only the Warrior's Trace as a potential route for invasion into the Tion Cluster.
The invasion resulted in the complete depopulation of the Kiirium Reaches, transforming them into desolate, radioactive wastelands with a scarcity of hyperlanes. Subsequently, these regions became known as the Ash Worlds.
In later times, the Tionese remembered the Devouring, albeit in a distorted manner, as a winter religious observance, with diverse customs across different worlds. Certain traditions, such as those practiced on Stalimur, involved a night of quiet reflection and the lighting of candles to repel malevolent spirits. Conversely, other traditions, like the Wakemeet festival on the planet Barseg, featured children costumed as evil spirits who would receive sweets from adults in exchange for a year's worth of blessings.
The destruction of the Kiirium Reaches was so thorough that even the knowledge of their geographical location was lost for thousands of years. In fact, it wasn't until the early stages of the Galactic Civil War that Ximologists were able to connect the Ash Worlds with the Devouring. Prior to this, it was widely believed that some sort of astronomical phenomenon, such as a supernova, had caused the devastation (although no concrete evidence of such an event had ever been discovered). The expeditions led by Bleys Harand and Henrietya Antilles largely unraveled the mystery of the Ash Worlds, with discoveries like the Antilles Map definitively linking the devastated planets in the region to the lost seats of power within Xim's empire.