During the early Imperial Era in the aftermath of the Clone Wars, the Galactic Empire occupied the world of Serenno in the Outer Rim Territories. Located deep in the space controlled by the Confederacy of Independent Systems, Serenno had been the homeworld of Count Dooku, the Head of State of the Confederacy. When the Empire came to the world, it attacked and conquered the former Separatist stronghold, wiping out at least one city.
With Serenno conquered, a company of clone troopers under Clone Captain "Wilco" were ordered to pillage the war chest from Dooku's former residence, Castle Serenno. During the operation, however, the rogue clones of Clone Force 99 arrived on-world to steal from the war chest, encountering the surviving Serennian city resident Romar Adell after their failure. While Clone Force 99 ultimately escaped, Wilco made note of their appearance in his report on the incident, leading to the captain's death at the hands of Vice Admiral Edmon Rampart when Wilco refused to write a falsified report that excluded any mention of the rogue clones. Having informed Moff Wilhuff Tarkin that Clone Force 99 perished during the fall of Tipoca City, Rampart declared he would write the new report to maintain his standing.