Who is Captain Rex in Star Wars?

According to Wookieepedia:

Rex, formerly designated CT-7567, was a veteran Clone Captain, Clone Commander, and Advanced Recon Commando who commanded the Grand Army of the Republic’s famed 501st Legion of clone troopers during the Clone Wars. Rex later served as a captain and commander within the Alliance to Restore the Republic during the Galactic Civil War.

Rex participated in many battles over the course of the Clone Wars. As the captain of the 501st, Rex served as second-in-command to Jedi General Anakin Skywalker, whose bravery and unconventionality in battle he came to share. In addition to being a close friend of Skywalker, he also became friends with Skywalker’s apprentice, Ahsoka Tano.

CT-T567, later given the nickname “Rex,” was like his fellow clone trooper, created from the genetic template of Jango Fett (Termura Morrison), a Mandalorian bounty hunter first seen in Star Wars: Episode II – Attack of the Clones (2002). Boba Fett and Omega from The Bad Batch were also created from Jango’s DNA, presumably with the hope of the Kaminaons creating the “perfect” soldier.

Rarely showing any flaws and continuing to improve in perseverance, integrity, and grit, Captain Rex is promoted to Commander in season seven of The Clone Wars, when the Grand Army of the Republic plans to invade the planet Mandalore with Ahsoka Tano, in what would later be known as the Siege of Mandalore.

Related: Should Ezra Bridger Be the Catalyst to Scrap the ‘Star Wars’ Sequels?

While a very important trooper in the Clone War era, Captain Rex adopted a less rigid approach as the Clone Wars continued and began looking at the bigger picture of life towards the end of the war. Referring to his fellow soldiers as “men,” not “clones,” Rex’s priorities were first and forever his clone brothers. He loved many as his own kin and was disgusted with Clone Sergeant Slick’s betrayal of the Republic during the Battle of Christophsis.

Rex was appalled by Order 66 — after his inhibitor chip was removed with the help of Ahsoka Tano — and the killing of his men while defending himself and Tano.

Many treated Rex more like a brother than just a friend, forming a close relationship with Jedi Master Obi-Wan Kenobi, Anakin Skywalker, and Ahsoka Tano. He was the #1 choice for any tough battle, as the Republic knew time and time again that Rex would get the job done the most ethical and humane way. He was, by far, the most important clone trooper in the clone wars.

Related: All-Star Directors Revealed For Favreau & Filoni’s Next ‘Star Wars’ Series

His character was enigmatic, as fans grew to love the clone captain more and more through The Clone Wars and Rebels, which featured an older Rex who survived Order 66 and remained a low profile throughout the galaxy.

Origin of Captain Rex in the Star Wars Universe

Like his fellow troopers, Captain Rex was created from the genetic tissue and DNA of bounty hunter Jango Fett on the planet Kamino.

Unbeknownst to the Jedi, a massive order of an army had been made for the Grand Republic by a thought-to-be-dead Jedi. This, for whatever reason, didn’t raise any red flags for the Republic or F, so they adopted these clones as soldiers for their oncoming war with the Separatist Alliance (Confederacy of Independent Systems).