Shortly after the formation of the Grand Army of the Republic, Jedi Knight Falon Grey was unaware that he started a secret project on Kamino: Grey was injured, Kamino was the nearest planet the Jedi could land on, and Lama Su promised to heal Grey if Grey gave Lama Su a small string of hair. Grey complied, and over the next few days Lama Su used the hair to form a clone. Lama Su named him X1.
Battle of TatooineEdit
Around 19 BBY, X1 and his brother, X2 were sent to Tatooine to inspect new clone troopers. The training session was stopped when a Confederate recon droid was spotted inside the outpost. After X1 ordered X2 to destroy the recon, he discovered an army of battle droids. The two brothers fought their way though the army and to a V-wing starfighter. X1 ordered X2 to take it scout ahead for more enemies, but just as X2 took off a Confederate cruiser jumped from hyperspace. X1 ordered X2 to abandon his ship, X2 jumped quickly and just as he did X2's ship blew up. X1 and X2, along with commanding general went to the main base and used ARC-170 Fighters to board the emery ship. X1 protected X2 when X2 used a v-150 anti-orbital ion cannon to take down the deflector shields of cruiser. They fled seconds before the ship had blown.
Battle of CoruscantEdit
Following the Republic's victory on Tatooine, X1 and his brother were called to Coruscant by Chancellor Palpatine, who held a ceremony for their bravery. As the ceremony ended, a fleet of CIS ships jumped from hyperspace. X1 commanded the ground force.
- Star Wars Battlefront: Elite Squadron