CT-7567 was a veteran clone trooper captain who led the Grand Army of the Republic's acclaimed 501st Legion during the Clone Wars. Bred and trained on the planet Kamino, CT-7567 entered into Republic service at the Battle of Geonosis in 22 BBY. He gained respect from Jedi officers and clone troopers alike as an honorable commander, becoming known as one of the best and toughest clone troopers in the Grand Army. He was even selected for specialcommand training under Advanced Recon Commando Alpha-17, following which he took the nickname "Rex." As the captain of the 501st, Rex served as second-in-command to Jedi General Anakin Skywalker, whose bravery and unorthodoxy in battle he came to share. He was close friends with Marshal Commander Cody, with their relationship mirroring that of their respective Jedi Generals, Skywalker and Obi-Wan Kenobi. The four of them often received joint assignments to coordinate front-line campaigns against the Confederacy of Independent Systems.
At the Battle of Christophsis, Rex became a mentor to Skywalker's newly assigned Padawan, Ahsoka Tano, with whom he forged a strong bond. He also managed to rebound from the following Battle of Teth, an engagement he would never forget due to the near-complete eradication of his 501st unit, Torrent Company. While on alistening post inspection tour with Cody, Rex rallied a small team of rookie soldiers to retake Rishi Station, which they thereafter destroyed to thwart Confederate General Grievous's planned invasionof Kamino. He was soon deployed on tour aboard Skywalker'sflagship, the Resolute, and joined Skywalker and Tano in leading 501st offensives at Bothawui, JanFathal, and other flashpoints across the galaxy. He took part in countless campaigns in the galactic theater of war, from thecontainment of the Blue Shadow Virus on Naboo and the liberation of Ryloth to other hard-won victories like theBattle of Malastare, the Second Battle of Geonosis, and the Battle of Kamino.
Throughout his career, Rex proved to be an effective leader who truly cared for the men under his command, even as he began to doubt his own future—and those of his clone brethren—in the Republic. The Battle of Saleucami of 21 BBY saw him meet the clone deserter Cut Lawquane, whom he came to respect despite their striking differences. His leadership was put to the ultimate test at the Battle of Umbara, when he was forced to unite the 501st Legion under an interim Jedi General, the obstinate and aggressive Pong Krell. Rex did not seeeye-to-eye with Krell and found himself having to balance his troops' well-being with Krell's high-casualty plans. When Krell manipulated the 501st into a fatal confrontation with their comrades from the 212th Attack Battalion, Rex realized their general was a traitor to the Republic, and he risked charges of treason to lead his men in arresting Krell. The ordeal refined his hard-line obedience to orders, as he also learned the value of making his own decisions as a soldier.
Rex's unwavering dedication to the Republic kept him on the front lines over the three-year span of the Clone Wars. He aided Skywalker, Tano, and Kenobi in rescuing Togruta colonists from the Zygerrian Slave Empireand, in 20 BBY, offered his soldier's expertise to help the Jedi train local insurgents on Onderon to emancipatetheir world. In a stark turn of events, he and Skywalker apprehended Tano on Coruscant after she was framed for a bombing of the Jedi Temple, an incident that culminated in her departure from the Jedi Order. In addition, Rex and Skywalker gave pursuit of a longtime comrade, ARC trooper Fives, who had gone rogue after unearthing an anti-Jedi directive that had been bred into all of the Republic's clone troopers. Before Fives could prove his findings to Rex and Skywalker, the Coruscant Guard gunned him down for resisting arrest. By war'send in 19 BBY, Rex ceded his command over the 501st to another officer, Commander Appo, who oversaw the unit into the rise of the Galactic Empire.
- REX: Aim, then fire. Rex, I bet sometimes even you miss. Speaking of, you're missing Jedi training.
Which is now. Remember? (SIGHS) You know, I can't be in two places at once. As a soldier, you're gonna have to learn to prioritize. Well, he's not a soldier. He's a Jedi.
- The Jedi General I served under combined the Force with his Wits.
- Blasters should be on kill not Stun.
- Brothers of the Broken Horn