Khar'Shan, the batarian homeworld, is wrapped less in mystery than in outright lies. Batarian propaganda claims the world has 15 billion inhabitants and an economy that rivals the asari. Although the legal slave trade does boost the batarians' profits somewhat, Citadel sanctions have left a paper tiger of an empire, one that fights rivals through deniable terrorist actions rather than the wars of its heyday centuries ago.
The Reapers will likely be the death blow to that empire. Almost no information has escaped Khar'Shan since the Reapers destroyed the comm buoys, but batarian refugees say that resistance has created a bond among commoners. If a new government can rise from the ashes, that bond may sustain a new batarian society.
The planet 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.