The First Sith Imperial Strikeforce represented a specialized group inside the Imperial Navy. It was comprised of individuals from both the One Sith order and officers from the Navy, notably those belonging to Skull Squadron. Grand Admiral Rulf Yage, along with his colleague Moff, the Chiss named Fehlaaur'aitel'loro, held command over this unit. In the year 137 ABY, Regent Morlish Veed dispatched the strikeforce to execute Operation: Thunderstroke. This operation's objective was the capture of Emperor-in-exile Roan Fel on the planet Agamar. The highest-ranking Sith member within the strikeforce was Darth Rauder, who supervised all pilots, regardless of whether they were Sith or not.
During the resulting conflict, the strikeforce's primary vessel, the War Hammer, successfully eliminated the Star Destroyer Dauntless, which was loyal to Fel and under the command of Admiral Tohri Challon. However, they were unsuccessful in preventing Roan Fel's departure aboard his shuttle.