Stalwart, a Victory I-class Star Destroyer, functioned as the flagship of then-Vice Admiral Thrawn, with Commander Maloc in command. Its service occurred about one year before the Battle of Endor.
During the Battle on the Frontier, Thrawn oversaw the building of the space station NL-1 within the Pakuuni system from the bridge of the Stalwart. The station also acted as a base of operations for operations targeting the Pakuuni Pirates and Rebels endangering it, with Maarek Stele's piloting skill contributing significantly to these efforts.
After NL-1 was finished and the Pakuuni Pirates were defeated, Thrawn transferred his command from the Stalwart to the Imperial I-class Star Destroyer named Vanguard.