Taskforce Vengeance

A large fleet of Imperial warships during the Galactic Civil War intending to destroy a Rebel shipyard in the Nocto System, the Rebel presence in the Airam Sector, and secure the Airam Sector as an Imperial asset. The fleet was led by Admiral Senn onboard his flagship, the Executor-class Star Dreadnought Vengeance. Other major warships in the fleet included the Imperial Star Destroyer Rage and the Immobilizor 418 Cruiser Compellor. In the end, Admiral Senn and the Vengeance were destroyed by an intense Rebel attack. Both the Rebels and the Imperials in Airam were significantly damaged and left stalmated. Taskforce Vengeance failed to destroy the Rebel presence in the Airam Sector, nor force the compliance of the Airam leaders.

Source
Star Wars: X-Wing vs. TIE Fighter