Vanguard, an Imperial-class Star Destroyer, functioned under the command of Commander Ritton in the years following the notable Battle of Hoth.
During 2 ABY, the Vanguard deployed Imperial walkers which then paraded on Coruscant to commence the New Year Fete Week celebrations.
Notably, the Star Destroyer served as the flagship for then-Vice Admiral Thrawn during the attempted coup by Grand Admiral Demetrius Zaarin, an event that occurred approximately one year before the Battle of Endor.
After Zaarin successfully captured Emperor Palpatine from the Star Destroyer named Majestic, Palpatine was transferred by Zaarin to a Delta-class JV-7 escort shuttle with orders to rendezvous with Zaarin's command ship, the Glory.
Lord Darth Vader, alongside skilled pilot Maarek Stele, launched from the Vanguard in a TIE/sa bomber to assault the Glory, hoping to thwart the exchange and save the Emperor. Caught off guard, Zaarin was compelled to retreat, and the Vanguard successfully carried out the rescue of Palpatine.
Within the game Star Wars: TIE Fighter, the Vanguard is identified as an Imperial I-class Star Destroyer; however, it is incorrectly labeled as a Victory I-class Star Destroyer in the TIE Fighter Collector's CD-ROM: The Official Strategy Guide.