An Imperial took part in the Battle of the Sixela system against the forces of the Alliance to Restore the Republic. He was onboard Darth Vader's Interdictor Star Destroyer during the battle and communicated with Leia Organa when she tried to stop the fighting.
A number of months after the Battle of Yavin, Imperial Commander Rezi Soresh betrayed the Empire and fled retribution. In his exile, the former officer hatched a plan to take his revenge upon both sides of the Galactic Civil War. Soresh would draw the Rebellion to the Sixela system under false pretenses while at the same time trapping them with elements of the Imperial Navy.
This Imperial was accompanied Darth Vader to lead a fleet of Imperial Star Destroyers to the Sixela system. When the Rebel fleet came out of hyperspace, the Imperial fleet was ready. Trapping the Rebels with interdiction fields, the Imperial fleet engaged in brutal ship-to-ship combat with the opposing fleet, while Darth Vader landed on the planet to pursue Soresh.
When Rebellion leader Leia Organa escaped Soresh's compound on his barren moon, she contacted Vader's Interdictor Star Destroyer, which acted as the fleet's flagship; Organa reached this Imperial. She attempted to warn him of Soresh's plan to annihilate the system's star with resonance torpedoes. The only response the Imperial gave her was an angry tirade against the Rebellion. Organa cut off the channel when he laughed at her warning.
After Soresh's torpedoes reached the sun, it became apparent that the system would be destroyed, even though Soresh was already dead. Both fleets fled into hyperspace before the sun went supernova, vaporizing everything in the local area.
When this Imperial was contacted by Organa, he referred to her as "Rebel scum" and demanded her surrender. He refused to believe her warnings, offering a sharp bark of laughter.
This Imperial was introduced as a background character in the final book of Alex Wheeler's Star Wars: Rebel Force series.