The Annihilator was a Star Destroyer in the Imperial Navy during the Galactic Civil War. In 4 ABY, it served in the Imperial fleet defending the second Death Star. When the station was attacked by the Rebel Alliance, Imperial Commander Ciena Ree flew past the Annihilator to ensure its bridge was not attacked.
In 4 ABY, during the Galactic Civil War, the Annihilator was part of the Imperial fleet defending the second Death Star, an Imperial battle station situated over the moon of Endor. At that time, the station and its fleet were attacked by the Rebel Alliance, who hoped to destroy the Death Star.
During the battle, Imperial Commander Ciena Ree flew her TIE/IN interceptor around the Annihilator's bridge area, aware that a rebel pilot could crash their ship into it. However, she then recived the information that the Death Star's shield generator on Endor had been destroyed, opening up the station for attack from the rebels. Ree then witnessed the rebels destroy the Imperial flagship Executor, the next nearest Star Destroyer, and, just as she was about to attack a Mon Calamari Star Cruiser, all Imperial forces were ordered to retreat, forcing her to swoop away from the Annihilator. Shortly after, the rebels successfully destroyed the Death Star.