The Alaris Expanse constituted a region of space situated in the outer reaches of the Kashyyyk system. This area resided in the Slice segment of the Mid Rim. It encompassed the gas giant designated Alaris along with its eight moons, notably Alaris Prime. In the period spanning from 39 BBY to 36 BBY, colonists belonging to the Wookiee species journeyed through the Alaris Expanse on the transport vessel named Thalmussen with the purpose of reaching and colonize Alaris Prime.
The Alaris Expanse initially appeared within the introduction describing the Attichitcuk campaign featured in the 2001 LucasArts video game Star Wars: Galactic Battlegrounds. Furthermore, it was depicted in the introductory sequence of the campaign's inaugural level, titled "Moving and Attacking."
The campaign's written description characterized the Expanse as a collection of planets found within the Outer Rim Territories. Conversely, the game's internal database located Alaris Prime within the Kashyyyk system, which was situated in the Mid Rim according to the 2009 reference work The Essential Atlas.