In the year 0 ABY, Darth Vader, the Sith Lord, established a clandestine organization of secret forces devoted solely to him. This group's purpose was to delve into two critical matters: First, Vader aimed to uncover the identity of the Rebel pilot responsible for the destruction of the DS-1 Death Star Mobile Battle Station during the Battle of Yavin. Second, he sought to expose an individual secretly collaborating with the Galactic Emperor Sheev Palpatine behind Vader's back. To aid in these investigations, he enlisted the services of bounty hunters Boba Fett and Krrsantan. However, Vader also recognized the need for a dedicated private force of troops. Consequently, he recruited Chelli Lona Aphra, a renegade archaeologist, who in turn provided the assassin droids 0-0-0 and BT-1. Subsequently, the team journeyed to the planet Geonosis to acquire a portable droid factory. Vader then utilized this factory to construct his personal army of BX-series droid commandos. After Krrsantan apprehended Doctor Cylo, the individual who had been meeting with Palpatine, and 0-0-0 discovered the scientist's plans to create replacements for Vader, Vader led his commando droids into the skirmish in Cylo's research base.
Upon learning from Fett that the pilot who annihilated the Death Star was Luke Skywalker, a revelation that led Vader to understand the boy was his offspring, Vader's new primary objective became capturing Luke and converting him to the dark side of the Force. Vader, along with Aphra, 0-0-0, and BT-1, all made an attempt to seize Skywalker during the Battle of Vrogas Vas, but Luke managed to escape. Vader also deployed his commando droids into the War on Shu-Torun. When Palpatine became aware of the full extent of Vader's clandestine army, he expressed satisfaction with his Sith apprentice's covert actions, acknowledging that such behavior aligned with the principles of the Sith.