Khar'shan is the homeworld of the batarians.
Khar'shan is divided into multiple independent nation-states that co-exist under the umbrella of the Batarian Hegemony. These countries frequently clash and vie for leverage over each other, such as through acquiring weapons of mass destruction. The isolationist batarians heavily restrict direct interaction between Khar'shan and the rest of the galaxy.
In 2186 CE, Khar'shan was abruptly cut off from communications with the rest of the Batarian Hegemony. Hegemony officials claimed that comm buoys were being disrupted by solar activity, but the governor of the prominent colony of Camala accused the Systems Alliance of using stealth vessels to attack the homeworld. Refugees from the region later revealed that an unknown hostile species had attacked the Hegemony fleet and bombarded Khar'shan.