Senatorial arrests

"63 senators arrested in collusion with Jedi insurgency."

- The headline of the HoloNet News report of the arrests

One day after the formation of the Galactic Empire, Imperial Intelligence arrested sixty-three senators on charges of conspiracy and treason, all who were members of the Delegation of 2,000, a group of senators which tried to limit the growing executive powers of Supreme Chancellor Sheev Palpatine during the Clone Wars, and signatories to the Petition of 2,000. The event was reported on by the HoloNet News, with the news media outlet calling it a "dramatic victory over the Jedi rebellion."

Prelude
"In order to ensure the security and continuing stability, the Republic will be reorganized into the First Galactic Empire, for a safe and secure society!"

- Emperor Palpatine proclaiming the creation of the Galactic Empire

As the Clone Wars between the Galactic Republic and the Confederacy of Independent Systems entered its final stages by the year 19 BBY, Supreme Chancellor of the Republic, Sheev Palpatine, continued to gain emergency powers from the Galactic Senate. By the final actions of the war, former senators of the Loyalist Committee, displeased by the Supreme Chancellor's actions, formed the Delegation of 2,000, to counter Palpatine's growing political power, regularly partaking in the Cantham House meetings. One of the results of the meetings was the Petition of 2,000, a document signed by the entire two thousand strong delegation which served as a formal protest to Palpatine's political gains, and to return emergency powers back to the Galactic Senate at the end of the war.

Eventually, Palpatine declared the Jedi, keepers of peace and justice in the galaxy for thousands of years, and military officers in the Republic military, as traitors following an alleged assassination attempt, and quelled a supposed Jedi rebellion. Palpatine, secretly the Dark Lord of the Sith and enemy of the Jedi, Darth Sidious, sent his newly christened Sith apprentice, Darth Vader, to Mustafar to destroy the Separatist Council and shut down the droid armies of the Separatists, effectively bringing forth the end of the Clone Wars. Following the shut down of Separatist forces and the destruction of the Jedi Order, Sidious proclaimed that the Galactic Republic would be transformed into the first Galactic Empire, with him as its Galactic Emperor. The formation of the Empire was met by strong political and public support, with reactions to Palpatine's speech in the Galactic Senate Chamber being that of mass applause, though some&mdash;such as Senators Bail Organa and Padmé Amidala&mdash;watched in disappointment and dismay.

The arrests
"Imperial Intelligence scored a dramatic victory against the Jedi rebellion today, arresting sixty-three senators on charges of conspiracy and treason."

- HoloNet News reporting on the arrests

One day after the formation of the Empire, Imperial Intelligence, the espionage and anti-sedition agency of the Empire, cracked down on the political opponents of Palpatine on Coruscant, conducting the mass arrest, which resulted in the arrest of sixty-three senators of the Delegation of 2,000 and signatories of the Petition of 2,000. A number of those arrested were senators of prominent Core Worlds, although many were also aliens from planets in the Outer Rim Territories. A number of senators were also detained and forced to profess their absolute loyalty to the Emperor, including Mon Mothma and Bail Organa. Those arrested were loaded into a Theta-class shuttle by Imperial clone troopers.

Aftermath
"All those arrested had also been signatories to the Petition of the 2,000, a formal protest against Palpatine's new system of regional governorship that was signed by two thousand legislators and presented during the last full Senate session. Is your senator a traitor?"

- A HoloNet News report on the arrests

Following the mass arrest, the event was reported on by the HoloNet News, labeling it as a "dramatic victory over the Jedi rebellion." Before press time, a partial list of those taken into custody was released, revealing that senators Shea Sadashassa of Herdessa, Ivor Drake of Kestos Minor, Fang Zar of Sern Prime, Streamdrinker of Tynna, and Tanner Cadaman of Feenix were several of those apprehended. Of those arrested, Streamdrinker, Cadaman, and Drake were ultimately incarcerated at the Arrth-Eno Prison Complex on Coruscant and fatefully die in 0 ABY after an attempt to assassinate Emperor Palpatine and rescue the imprisoned senators went awry when it was revealed to be an Imperial scheme.

Legacy
"Bail and I were detained but released after we professed our loyalty. Why do I fight the Empire? One reason is my guilt."

- Mon Mothma reflecting on the arrests in the Rebel Files

Sometime after the creation of the Rebel Files in 5 BBY, the arrests were documented in the Files, with Mon Mothma adding a note stating how she was able to avoid being arrested and her profound guilt, which motivated her to continue to secretly oppose the Emperor and build up the Rebel Alliance. Decades after the end of the Galactic Civil War saw the New Republic, successors of the Rebel Alliance, as victors, and the rise of the First Order, the Rebel Files were uncovered on Durkteel. The Rebel Files eventually found their way to General Leia Organa, leader of the Resistance, as she was one of the only high-ranking members of the Rebel Alliance still alive. Organa, along with several other members of the Resistance that included Admiral Gial Ackbar, Vice Admiral Amilyn Holdo, and Poe Dameron, reviewed the Rebel Files to gain knowledge on how they may defeat the First Order, adding their own notes and feedback to the documents.

Behind the scenes
The senatorial arrests were first mentioned in the new Star Wars canon in the 2017 reference book Star Wars: The Rebel Files, written by Daniel Wallace. The event was originally created for the Star Wars Legends HoloNet News article "Republic HoloNet News Special Inaugural Edition 16:5:241," written by Daniel Wallace and Pablo Hidalgo and published in Star Wars Insider 84 in 2005.