The Imperial Base on Daro was a secret Galactic Empire training facility located on the otherwise-uninhabited Outer Rim planet Daro shortly after the Empire's formation. Hidden inside of a mountain, the base was situated around a large central ring, with turbolifts that connected to each level. It had several hangars, and its muster report included fifty clone Imperial commandos and 1,000 TK troopers. Shortly after the Empire's formation, the rogue clone commandos known as the Bad Batch entered the base to rescue Gregor, a commando who had attempted to desert from the facility.
In 19 BBY, the newly-fledged Galactic Empire had begun looking for a more cost-effective alternative to the clone troopers, who at the time formed the backbone of the Imperial Army. With the initiation of Project War-Mantle, 1,000 "TK troopers" were enlisted and sent to be trained at the Imperial Base on Daro. There, the recruits were instructed and trained by a contingent of 50 Imperial clone commandos, while also providing security for the base.
Clone Force 99, having been tasked by their contact, Captain Rex, to save a rogue commando named Gregor from the base, landed on the planet and infiltrated the facility. Not long after breaking Gregor out of captivity, the team was compromised by a clone commando and his squad of TK troopers, though they were swiftly dispatched. The extraction team ran through the facility, and engaged numerous TK troopers and their clone instructors in intense firefights. Eventually, the team managed to extract through the base's reactor port, but the squad's leader, Hunter, slipped and plummeted off the mountainside of the base. Though he survived, he was surrounded by Imperial troops and captured.