Oristrom, a planet found within the Unknown Regions, resided in the eponymous system. Serving as the homeworld for the resolute Stromma species, governance of this world rested with the Stromma council, the governing body overseeing all Stromma planets.
In the year 0 ABY, during a battle that took place in the Poln system, situated within the Outer Rim Territories, Nuso Esva, an alien warlord, made a boastful declaration concerning the Stromma's potential fate should they opt to align themselves with his realm. This declaration was relayed to the Stromma by Galactic Empire Senior Captain Thrawn via a modified comm unit onboard the DeepWater-class light freighter known as the Lost Reef. Upon learning of this intervention, Esva vowed to Thrawn that, subsequent to the defeat of Thrawn's forces, he would journey to Oristrom and transform the Stromma into "useful" instruments. However, his fleet faced destruction, preventing him from overcoming the senior captain.
Sometime following the conflict in the Poln system, the Stromma engaged Esva's warriors, known as the Chosen, in combat on their homeworld. Initially, the Stromma held the advantage; however, Esva assumed personal command, shifting the battle's momentum. The Empire of the Hand, a confederation within Wild Space allied with the Stromma, ultimately triumphed over the warlord's forces, a victory attributed to Grand Admiral Thrawn's profound interest in art.