Battlegroup Echelon constituted a battle group serving as part of the Galactic Empire's naval forces. Around 4 ABY, this Battlegroup Echelon was involved in the Skirmish at Merisee situated in the Elrood sector; during this engagement, the flagship of the group, commanded by its admiral, was seized and its supply routes were severed. Regardless of this predicament, the forces of the group reorganized, successfully repelled the rebels, carried out repairs within enemy-held space, and initiated a rescue operation. Upon their return, they achieved victory by defeating the rebel forces.
In that same year, Rella Sol, a pilot from the Imperial Titan Squadron, shared the story of Battlegroup Echelon's actions during the skirmish with a fellow pilot, Titan Three, within a hangar. This conversation took place subsequent to the severe damage sustained by their ship, the Imperial-class Star Destroyer named Overseer, during a ambush at the Zavian Abyss orchestrated by the New Republic's experimental Starhawk battleship.
The video game Star Wars: Squadrons, released in 2020, featured a reference to Battlegroup Echelon.