The Sara system was initially catalogued by freelance prospectors and colonized by an expedition from Tarsonis several years later. Mar Sara formed the eighth of the thirteen core colonies of the Terran Confederacy. The Sara system was unusual for having two habitable planets, but Mar Sara was always a backwater colony compared to the more prosperous Chau Sara. Mar Sara was one of the first planets to be infested by the zerg when they appeared in terran space. It was also the first planet on which the Confederates fought the advancing Swarm to any significant extent, although most of the actual fighting was done by local militia forces.