They are genetically engineered to age at twice the rate of a normal human in order to be ready for deployment much quicker, and be unquestionably loyal to the higher chain of command.

At the end of the war, Palpatine, the Republic's leader and secretly a Sith Lord who orchestrated the conflict to gain political power, issues Order 66, which brands the Jedi as traitors and forcibly compels the clone troopers, under the influence of an inhibitor chip implanted in their brains, to execute them.

Lucas intended for the prequel trilogy to depict the evolution of the galaxy's fighting forces, and the clone troopers were the step after flawed battle droids.

When Order 66 is issued by Sidious during the series finale, the activated inhibitor chips forcibly brainwash the Clone Troopers into believing their Jedi generals as traitors to the Republic and subsequently executing them.

The 2014 animated series Star Wars Rebels features a group of former clone troopers, including Rex from the preceding cartoon, who had their chips removed and therefore did not carry out Order 66.

Most of the squad evades the effects of Order 66 due to their unique genetic alterations that prevent their inhibitor chips from functioning, except for Crosshair, who is reprogrammed by Admiral Tarkin to serve the Empire.

Clone troopers themselves react negatively towards the change as they were bred and raised to fight in combat but now are forced to defend isolated bases or retire indefinitely.

[14] In the novels Lords of the Sith by Paul S. Kemp, and Tarkin by James Luceno, several clone troopers are still in active service during the early years of the Empire's reign, such as among stormtroopers serving Darth Vader, and even among the Emperor's elite Imperial Guard.

[15] Marshal Commander Fox, CC-1010, led the Coruscant Guard, an elite clone trooper unit assigned to serve as peace-keepers on the Galactic Republic capital.

Like every other clone trooper in the Guard, Fox was bound by honor and duty to protect and serve the Supreme Chancellor and the members of the Galactic Senate.

Additional sources state that Fox continued his duty on Coruscant, until an error on his part led Darth Vader to execute him by force snapping his neck.

Notable sub-divisions within the 501st Legion include: During Star Wars Celebration 2016, Dave Filoni stated that in a planned story arc for The Clone Wars, Ahsoka, who has left the Jedi Order, is given (honorary) command of part of the 501st Legion, 332nd Company, including Captain Rex; those under her command repaint their helmets orange and adorn them with Ahsoka's togruta (lekku) markings.

Now a much older man because of his accelerated aging, he lives on the wasteland planet Seelos and hunted worm-like joopa with fellow clones Wolffe and Gregor before they are offered a place in the Rebel Alliance, which leads to Rex reuniting with Ahsoka.

He first appears in Episode III: Revenge of the Sith, in which he and other members of the 501st carry out Order 66 and follow Anakin, now Darth Vader, in attacking the Jedi Temple on Coruscant.

Story reels for a previously unfinished four-episode arc called "Bad Batch" (initially part of The Clone Wars Legacy project, the episodes were later released on Disney+ in their completed state) revealed that Echo survived and was captured by the Separatists.

He remained with them beyond the end of the Clone Wars and avoided obeying Order 66 like most of them, though this was mainly due to his inhibitor chip being damaged during Separatist captivity, rather than their mutations allowing them to resist it.

After his promotion to ARC trooper, Echo also wears light gray pauldrons on his shoulders and a kilt-like kama painted in an asymmetrical white and blue design.

Later, after his rescue from Separatist capture, he is visibly a cyborg, with various apparatus protruding from his head and a droid plug in place of his right hand; post-rescue, he takes to wearing what appears to be a stripped-down variant on standard Phase II armor.

Though their actions allow a Republic victory, Krell, without process of a court-martial, finds Fives and Jesse guilty of treason and sentences them to execution by firing squad.

In season four's Battle of Umbara, Jesse, like Fives comes to consider General Pong Krell to be ruthless and reckless (mainly over the casualty numbers).

The battalion fought on a multitude of worlds throughout the Clone Wars, including early campaigns on Christophsis, Teth, Ryloth, Saleucami and Geonosis, to latter battles on Kiros, Sarrish, Moorjhone and Umbara.

He is characterized as a cautious but "natural and practical leader" whose "keen ability to strategize, combined with his fierce combat style in the heat of battle, earned him the respect of the Jedi, and of his fellow clones".

[30] Captain Gregor, CC-5576-39, is the former leader of Foxtrot Group, an elite commando unit within the Special Operations Brigade of the Grand Army of the Republic, attached in direct support to the 212th Attack Battalion.

[31] He is introduced in the season five episode "Missing in Action"—suffering amnesia and living on the distant planet Abafar, where a stranded D-Squad—a Republic covert-ops unit consisting of droids looking for a Separatist decoding chip—discovers him working as a dishwasher in a diner.

Gregor holds off Separatist droids to allow the Republic mission to escape, and despite his promise to make his way home, he is seemingly killed in an explosion of rhydonium.

When the Spectres, a team of rebels from the planet Lothal, arrive on Seelos to ask for help, Gregor initially declines, but eventually assists them in fending off an Imperial attack after Wolffe inadvertently exposes them to the Empire.

Gregor's commando armor bears yellow markings and an off-white camouflage pattern, and his helmet is adorned with hash-marks modeled after those on Gerry Cheevers' hockey mask.

Neyo and his troops were stationed on the Outer Rim world of Saleucami, under the command of Jedi General Stass Allie, in the waning days of the Clone Wars.

[36] Afterward, he appears with a redesigned character model, including a cybernetic eye implant caused by a fight with Separatist assassin Asajj Ventress, and leads a tight-knit unit nicknamed Wolfpack on the battlefield.

[46][47] The squad was introduced in the seventh season of The Clone Wars animated series, where they came to Anaxes to assist Anakin Skywalker, Obi-Wan Kenobi, and Rex on their mission to investigate a source of Separatist victories, as well as try to rescue Corporal Echo, the ARC Trooper who was presumed dead on Lola Sayu and is revealed to have been captured by the Techno Union and held on Skako Minor.