The Imperial-class Star Destroyer known as Vengeance served as the vessel of High Inquisitor Jerec.
Vice Admiral Slenn had the use of the Star Destroyer Vengeance during the Attack at Datar. A contingent led by Nahdonnis Praji was assigned duty aboard the Vengeance with orders to disrupt Rebel Alliance supply lines on the planet. During the conflict, Slenn inadvertently alerted the Rebels to the impending Imperial assault, prompting a fierce, last-stand resistance. Lord Darth Vader, angered by the failure to capture any Rebels alive, executed Vice Admiral Slenn for his blunder. Later, the Vengeance participated in the Battle of Nar Shaddaa.
Later on, the Vengeance became the flagship of High Inquisitor Jerec, with Captain Thrawn deployed by Emperor Palpatine to both support Jerec and command the ship. The Chiss officer was frequently assigned to the Vengeance so that he could keep the Dark Jedi in check, as the Emperor was fully aware of the nature of his servant's true ambitions. Some of the Imperial crew, indoctrinated with humanocentric propaganda, were uneasy serving under a blue-skinned alien and a seemingly blind "walking skeleton". Under the joint command of Jerec and Thrawn, the Vengeance spearheaded the brutal campaigns to subjugate Sulon under Imperial rule, deploying the Ghost Battalion and other Imperial Special Operations units. Morgan Katarn, the local Rebel leader and a person of interest to Jerec, was captured and brought aboard; Jerec executed him after Katarn refused to become his apprentice.
Although the Spore destroyed this ship, Jerec was able to recover its computer core and transfer it to a new Star Destroyer, which he named Vengeance II. After relinquishing the Vengeance II to Death Squadron, the personal flotilla of his primary rival, Lord Vader, who had recently been appointed by the Emperor as Supreme Commander, Inquisitor Jerec renamed his final flagship Vengeance as well, seemingly reluctant to abandon the name of his former Star Destroyer.