The Cathar Prime system is located along the edge of the Quelii sector, close to the Pil Diller system. This seclusion from the majority of the sector has allowed a unique sentient race to evolve: the Cathar. These beings share their name with the single planet in the system on which they developed. With no other bodies in the night sky, other than their sun and the stars of other systems, the Cathar did not yearn to reach for space quite as much as other sentient species. As a result, Cathar Prime remained fairly undeveloped by the natives and in turn was left vulnerable to outsiders, such as the Mandalorian Neo-Crusaders, who attacked and conquered the system at the start of the Mandalorian Wars. That attack was a form of punishment for the Cathar, since they fought against the Mandalorians during the Great Sith Wars. It was also said to be a comparison exercise; testing the Mandalorian battle skills against those of the Cathar.

After this conflict, the Cathar race was nearly eradicated, and most survivors fled the system to live on other planets. However, in more recent times, a steady stream of refugees have begun returning to Cathar Prime to rebuild their shattered homeworld and reestablish the system's former glory. Following them have been a string of foreign influences, such as a dark and mysterious group that took the system as a base of operations. Alternatively referred to as occupiers or caretakers, the non-natives have wrought many changes within the system's space and on the single planet over the past few hundred years, but the Cathar still maintain their independent culture.