The Battle of the Omarion Nebula was a battle of the Imperial Period that took place in 18 BBY. Although the Empire had been forced to withdraw from the area after the Battle of Delta Vega, they were able to re-establish a base there shortly after. Imperial Intelligence was able to decode a message that revealed the location of the stronghold of the Unified Resistance. As the Empire needed the hyperspace routes that passed the planet in order to continue their subjugation of the Outer Rim, a task force of the Imperial Navy was dispatched to wipe it out.
Although Rebel resistance was fiercer that expected, under cover of the artillery bombardment, the navy made their way to the rebel space station in a three pronged attack. While the two fleets battled it out, a platoon of stormtroopers infiltrated the space station and set explosive charges. After shutting off the droid control signal, they escaped the base moments before it was destroyed, resulting in a Imperial victory.