As indicated by the war's name, this was the first major military conflict in the Tangeal Expanse between organized nation-states.
The primary cause of the war were disputes in ownership of eezo deposits on the Joseo-Yuke frontier. Major theater of operations in the war was the star system known today as Overlord's Fall. Many naval battles, flanking maneuvers and pincer movements were conducted in Overlord's Fall, shifting the fronts back and forth, but ultimately Federation of Yuke gained the upper hand, forcing Joseo to withdraw and concede defeat. The contested system was christened Second Aralakh in honor of the krogan home system's star and replaced its former star catalogue name.