Battlegroup Echelon was a battle group within the Imperial Navy of the Galactic Empire. At some point prior to the ambush at the Zavian Abyss against the New Republic, Battlegroup Echelon participated in the Skirmish at Merisee, where the formation's flagship, led by their admiral, was captured and their supply lines were cut. Despite the situation, they rallied and defeated the hostile enemy, made repairs in enemy territory, and launched a rescue. When the unit returned, they defeated the rebel forces and emerged victorious.
Imperial Titan Squadron pilot Rella Sol recounted Battlegroup Echelon's efforts at the skirmish to Titan Three in a hangar after their vessel, the ISD Overseer, was heavily damaged in the battle at the Zavian Abyss against the New Republic's prototype Starhawk battleship.