During the Imperial Era's initial period, following the conclusion of the Clone Wars, the Galactic Empire took control of the planet Serenno, situated in the Outer Rim Territories. Serenno, located far within the space dominated by the Confederacy of Independent Systems, formerly served as the homeworld of Count Dooku, who was the Confederacy's Head of State. Upon their arrival, the Empire launched an assault, seizing the former Separatist stronghold and wiping out at least one city.
After Serenno's conquest, a company of clone troopers under the command of Clone Captain Wilco received orders to seize the war chest located in Dooku's former home, Castle Serenno. However, during this operation, the renegade clones comprising Clone Force 99 landed on the planet with the intention to steal from the war chest, and after their mission failed, they encountered Romar Adell, a surviving resident of a Serennian city. Although Clone Force 99 successfully escaped, Wilco documented their presence in his report about the event. This led to the captain's death at the hands of Vice Admiral Edmon Rampart when Wilco refused to submit a false report omitting any mention of the renegade clones. Rampart, having previously informed Moff Wilhuff Tarkin that Clone Force 99 had died during the fall of Tipoca City, declared that he would create the new report to protect his reputation.