Also known as CT-27-5555, Fives trained with Domino Squad on Kamino before being shipped out to the Rishi Moon listening outpost. He survived the Separatist attack on the station there, and was transferred to the 501st Legion alongside his squadmate and fellow survivor, Echo. Fives and Echo were promoted to ARC trooper status after the defense of Kamino from Separatist invaders.
He and Echo were later assigned with the difficult mission of freeing Republic prisoners from the daunting Citadel prison installation on Lola Sayu. Though Fives survived that arduous assignment, Echo tragically fell in battle, leaving Fives as the sole survivor of the Domino Squad training squad.
When Fives was just a rookie stationed at the Rishi Moon listening post, it was infiltrated by commando droids determined to prevent the outpost from detecting an impending attack. This incident coincided with an inspection tour by Clone Captain Rex and Commander Cody, who took command of the rookie squad and shaped them into an effective fighting force.
Fives' days as a clone cadet were fraught with difficulty and embarrassment. Domino Squad simply lacked the unit cohesion necessary to survive in the battlefield, and the clones constantly failed their training exercises. Clone 99, a maintenance clone who would witness these tests from the sidelines, nonetheless had faith that Domino Squad would someday excel.
Fives was born in the clone hatcheries of Kamino, and spent his accelerated formative years training to be a soldier in the Galactic Republic. Like his clone trooper brothers, Fives regards Kamino as home, and he fought bravely to defend it from Separatists.
ARC Trooper Fives served on special assignment during the Republic invasion of Umbara. He served alongside Clone Captain Rex and General Pong Krell during the costly mission to retake the shadowy planet.
General Pong Krell was responsible for numerous Republic victories in the Clone Wars, but the casualty rates of the clone troopers under his command were appalling. Though Fives wanted to support Clone Captain Rex during the grueling Umbaran mission, he grew increasingly wary of Krell's orders.