Inquisitor was a designation employed within the Inquisitorius Program, a component of the Galactic Empire. Functioning as agents of the dark side on behalf of the Empire, their primary mission was to hunt down the remaining Jedi following Order 66, with the objective of either eliminating them or recruiting them into the Inquisitorius, where they could be compelled to serve Darth Sidious.
The Inquisitors were under the command of the Grand Inquisitor. Throughout the Imperial Era, an individual with this title served as the Grand Inquisitor, while the Third Sister briefly held the position during 9 BBY. Inquisitors of lesser rank were referred to as Brother or Sister, accompanied by a number assigned after they had slain their first Jedi and demonstrated their worth. Examples of such Inquisitors include the First Brother, Second Sister, Third Brother, Third Sister, Fourth Sister, Fifth Brother, Sixth Brother, Seventh Sister, Eighth Brother, Ninth Sister, Tenth Brother, Eleventh Brother and Thirteenth Sister. Other individuals who served as Inquisitors include Barriss Offee, Tualon Yaluna, Jerserra's master, and an unidentified Inquisitor.
Those who were inducted into the ranks of the Inquisitorius relinquished their former identities and adopted new designations, identified as Brother/Sister to reflect their gender.
Inquisitors, holding a position of authority within the Galactic Empire, were primarily responsible for locating and either capturing or eliminating young Force-sensitive beings, including former Jedi, Padawans, and individuals from various Force-related traditions. Inquisitors also functioned as enforcers, suppressing political dissent and threats such as rebel groups and supporters of the Old Republic. The specifics of their nature, purpose, and composition were concealed from the majority of the Empire's branches.
As agents answering to the Dark Lord of the Sith Darth Vader, Inquisitors possessed significant influence within the Empire. They were granted the authority to requisition and command Imperial resources necessary for their missions, directly commanded Purge Troopers, and some even held the rank of commander within the Inquisitorius. Nevertheless, Inquisitors were subordinate to the Grand Inquisitor and other high-ranking Imperial officials, including a Grand Moff.
During their initial years of service, the Inquisitors exhibited weakness in their command of the dark side of the Force, as their combat techniques mirrored their earlier Jedi training. To address this deficiency, Darth Vader instructed them to transition from a defensive fighting style to a more aggressive one. Some of Vader's training exercises resulted in Inquisitors losing limbs, serving as a lesson in the nature of loss. As servants of the Sith, Darth Sidious also ensured that the Inquisitors were not granted full access to the knowledge and abilities of a Sith Lord. Over time, Inquisitors developed their power and skills, but only to the extent permitted by their Sith masters, eventually earning recognition as some of the most proficient combatants in the galaxy.
Among the known Inquisitors, Seventh Sister, Second Sister, and Ninth Sister were notable examples of distinguished individuals whose abilities made them some of the most lethal fighters within the Inquisitorius.
The Inquisitors wore bodysuits of black and grey, supplemented with armor, and wielded crimson-bladed lightsabers. Typically, Inquisitors utilized double-bladed spinning lightsabers, featuring a spinning mechanism that allowed the saber to rotate automatically, enhancing their ability to deflect incoming attacks. Inquisitors might also be equipped with other armaments, such as S-Mine Detonators.
The Inquisitor rank was in use by 19 BBY, following the implementation of Order 66. Fearing the threat posed by the surviving Jedi to his authority, Darth Sidious established the Inquisitorius with the aim of tracking down and either corrupting or eliminating the remaining Jedi. Sidious then assigned his Sith apprentice, Darth Vader, the task of training the former Jedi in the ways of the dark side, transforming them into Inquisitors under his command. The Inquisitors were led by the Grand Inquisitor, who was personally chosen by the Emperor and collaborated with Vader. As the Dark Lord of the Sith, Vader oversaw the Inquisitorius on behalf of his master, Darth Sidious. Some members of the wider Galactic Empire held a negative view of the Inquisitorius. For example, Imperial Security Bureau chief supervisor Lank Denvik questioned the effectiveness of the Inquisitorius, referring to the Inquisitors as "armored abominations".
In 14 BBY, the Second Sister and Ninth Sister pursued the Padawan survivor Cal Kestis and his crew aboard the Stinger Mantis. The Second Sister took a particular interest in Kestis, using him to locate Eno Cordova's holocron, which contained a record of Force-sensitive children compiled during the final days of the Jedi Order, in an attempt to gain favor with the Emperor. Ultimately, both the Second Sister and Ninth Sister were defeated by Cal Kestis. The former experienced a change of heart after her former Jedi Master, Cere Junda, apologized for her role in her transformation into an Inquisitor. Darth Vader, viewing her change of heart as a failure, executed her. The Ninth Sister was eventually killed by Kestis in 9 BBY on Coruscant.
Sometime between 18 and 5 BBY, the Eleventh Brother was informed of Ahsoka Tano's presence in a farming village. After burning the village, Tano engaged him in combat and ultimately killed him.
Blaise Zirkonn, a Force-sensitive agent of the Inquisitorius who worked with the organization for nearly a decade, aspired to be promoted to the rank of Inquisitor. In 4 BBY, following the death of the Grand Inquisitor, the Seventh Sister became an important commander within the Inquisitorius. She and other Inquisitors sought to succeed their former leader as the new Grand Inquisitor, though she was eventually killed along with the Fifth Brother and the Eighth Brother.
In time, the Empire concluded that the Jedi were extinct, and the Inquisitorius were believed to have disappeared along with them, particularly following the death of the Grand Inquisitor. Around the time of the Battle of Yavin, Vader was considered to be the last vestige of the Jedi religion within the Empire. However, Vader prevented the Grand Inquisitor's spirit from passing on, transforming him into a trap for any aspiring Jedi who ventured to the Tempes Jedi outpost. Furthermore, an Inquisitor of humanoid form named Marrok remained active during the New Republic Era even after Vader's death. Marrok became a mercenary and was employed by Imperial loyalist Morgan Elsbeth. This mysterious Inquisitor assisted Elsbeth in her efforts to locate Grand Admiral Mitth'raw'nuruodo "Thrawn," whose return to the galaxy had the potential to unite the fractured Imperial remnants.