Gesselle Organa was a general in the Galactic Republic, an Alderaanian Human female, and a member of the House of Organa. Her service took place during the times of the Cold War and the Alderaan Civil War.
During the Alderaan Civil War, Gesselle Organa and her forces were tasked with defending a highly potent force field. This field was powered by drawing energy directly from Alderaan's planetary generator. Their enemy was the House of Thul, supported by the Sith Empire. A Sith apprentice of Darth Baras infiltrated their defenses and sabotaged the generator, forcing it into backup mode. This action cut off the excess power required, resulting in the deactivation of the Organa force field.
Following the sabotage of the planetary generator by the Sith Warrior, which led to the deaths of numerous soldiers, Organa, accompanied by Blenks, Kan'grell, and Prinn, confronted the Sith. The Sith was seeking information regarding Jaesa Willsaam, who had previously been Organa's handmaiden. Organa attempted to negotiate with the Sith, but her offer was rejected. The Sith then began to torture Blenks, who was Organa's lover. Unable to bear witnessing his impending death, Organa revealed that the parents of Jaesa Willsaam, a Jedi Padawan, were still employed as servants at Castle Organa. After obtaining the information about Willsaam's parents, the Warrior proceeded to execute Organa and her bodyguards for their defiance against the Empire.