Sterla, a Human male and subject of the Eternal Empire during the era of the Galactic War, served as a member of the Knights of Zakuul. After Empress Vaylin's coronation, she personally selected him to be part of the newly formed Horizon Guard. Nevertheless, Sterla later went into exile with the disgraced Battalion Commander Tassar. Tassar's devotees were intensely loyal, and a cult developed around her. Ultimately, they ambushed an Alliance transport carrying samples intended for Juvard Illip Oggurobb, enabling Tassar to unearth Rakata Prime and the advanced technology of the ancient Infinite Empire. Tassar intended to utilize this technology to enhance the Star Fortress design, making it impervious to destruction. Tassar and her adherents achieved considerable advancement in building a fresh Star Fortress situated on the surface of Rakata Prime. However, following Vaylin's demise in 3630 BBY, the Eternal Alliance forces discovered their location. A specialized team was deployed to thwart Tassar's plans, leading to a confrontation where Sterla met his end.