The Stalwart, an Imperial-class Star Destroyer, operated as part of the Imperial Navy during the Galactic Empire's era. Functioning as the flagship for Admiral Kinshara's One Twenty-Fifth task force, the Star Destroyer saw action in 2 BBY.
Around that time, a group of insurgents from the Denash system found themselves in conflict with Wistran, the governor of that region. This was just one instance of unrest occurring across the Batonn sector. As part of the Empire's efforts to suppress the burgeoning rebellion in the sector, Fleet Admiral Jok Donassius tasked the One Twenty-Fifth with engaging the Denash insurgents. The goal was to prevent them from reinforcing the larger rebel group located on the planet Batonn. The battle concluded with Admiral Kinshara and the One Twenty-Fifth securing victory due to the limited insurgent presence in the system, resulting in the capture of a rebel base. However, the prisoners revealed during interrogation that the majority of the insurgents' ships and resources had already been relocated to Batonn. Kinshara subsequently reported this information to Donassius.
The Stalwart was initially referenced within the 2017 novel Thrawn, which represents the initial installment in Timothy Zahn's Star Wars: The Imperial Trilogy.