Treason

"I remember what it was like before your ships showed up, before you Imperials ruled Lothal like the rest of the galaxy.''" "Mister Grint, that sounds like treasonous talk to me." "''That it does, sir."

- Yoffar, Commandant Aresko and Taskmaster Myles Grint

Treason, also known as treachery, was criminal action against a legitimately recognized government or someone who served that government. In the Galactic Empire, the definition of treason was such that merely speaking against the Empire or its policies was sufficient to place one under arrest, often without trial or other due process. "Traitor" was the formal term for an individual that had committed treason.

History
"They are obviously skilled at committing high treason."

- Kylo Ren, insulting Armitage Hux's stormtroopers following Finn's betrayal

During the Battle of Umbara, Jedi General Pong Krell was revealed to be a traitor to the Galactic Republic.

Placed on trial for the bombing of a hangar at the Jedi Temple on Coruscant, Ahsoka Tano was accused and convicted of murder and treason against the Jedi Order and Galactic Republic, but the true culprit, Barriss Offee, was exposed before she could be sentenced. All charges against Tano were dropped, but the young Togruta chose to reject the Jedi Order's offer to rejoin their ranks, as they had not stood by her during the trial.

When the Jedi attempted to arrest Supreme Chancellor Sheev Palpatine after he refused to surrender control back to the Galactic Senate upon the defeat of General Grievous, he declared "It's treason, then" and engaged them in lightsaber combat.

Approximately five years after the end of the Clone Wars, Darth Sidious began to suspect that one or more officials of the Galactic Empire on Ryloth were guilty of treason, due to a series of attacks by members of the Free Ryloth movement that could not have enjoyed the level of success that they did without help from someone inside the Empire. He decided to lead a personal mission to Ryloth to root out the treachery, bringing along his Sith apprentice and feared agent Darth Vader with him. His suspicions were correct, as the Imperial colonel Belkor Dray had for years been supplying information to the Free Ryloth movement in an attempt to discredit his superior, Moff Mors, in the hope of claiming her position. During Sidious and Vaders' mission, he was manipulated into his greatest treachery yet, aiding the Free Ryloth movement in a direct attack on their personal command ship, the Perilous, and then in tracking the two Sith Lords when they escaped to the planet. He also manipulated matters to his own ends by having the rebels attack the vessel of Moff Mors as well. Dray eventually paid for his treason with his life when Moff Mors realized the extent of his activities and had him shot by a V-wing starfighter, an attack he chose not to evade.

When a couple of Imperial agents harassed Yoffar about not having a license for selling Jogan fruits, Yoffar grumbled that he remembered what life was like before Imperials ruled Lothal like the rest of the galaxy. Commandant Cumberlayne Aresko described his words as treasonous and tried to place him under arrest for it, but a timely distraction by Ezra Bridger allowed Yoffar to remain free. Later, Bridger encountered the residents of Tarkintown, many of which had been placed under arrest for similar "treasonous" statements.

During his time at the Academy for Young Imperials and later the Arkanis Academy, Zare Leonis, an Imperial cadet, secretly participated in treasonous activities against the Galactic Empire. Despite this, when an Imperial crackdown began on the planet Lothal and fellow cadets reported hearing rumors that a cadet at the Pretor Flats Academy had been taken away by stormtroopers for admitting to treason, Leonis dismissed such rumors. Playing the role of the model cadet he urged his fellow cadets not to believe what he referred to as "friend-of-your-brother" nonsense. Later, Leonis's own treachery was discovered at the Arkanis Academy. He was made to attend a tribunal and sentenced to death by firing squad, but escaped before the punishment could be carried out.

Following an Imperial crackdown on the planet Lothal, a once loyal Imperial official, Minister Maketh Tua, felt increasingly conflicted regarding the Empire's brutal tactics in searching for a group of rebels that had long troubled Imperial operations on the planet. Also fearing for her own life, she chose to commit treason by defecting from the Empire, promising the rebels information on other rebel sympathizers in exchange for their help in spiriting her away from the planet. Her attempt at defection was not successful, as her actions were tracked by the Empire, and she was killed in a blast orchestrated by the Empire and overseen by Darth Vader. The rebels were then blamed publicly for her death.

Though it did not always refer to it directly as such, the Galactic Empire considered any rebellion against it to be treason. When he captured Princess Leia Organa, Darth Vader was unsympathetic to her pleas, describing her as "a member of the Rebel Alliance and a traitor." He then subjected her to harsh torture, hoping to extract information from her regarding where she had hidden the stolen Death Star plans.

Following the pivotal events of the Battle of Endor, Imperial Governor Adelhard described reports of the destruction of the Death Star II and the deaths of Emperor Palpatine and Darth Vader as treasonous rumors. He then established the Iron Blockade and began persecuting those who spread such "rumors."

The defection of the stormtrooper FN-2187, later known as "Finn," was considered an act of high treason by the First Order. Following his defection, several individuals in the First Order such as FN-2199 and Kylo Ren called him out as a traitor.