Being a largely industrial planet, Correllia could provide excellent spaces for vast droid factories. In 21 BBY, the Confederacy of Independent Systems sent a droid army to the planet of Correllia, in an attempt to capture a crucial core world to their inventory. Unaware to the battalion, another Separatist base had been constructed, later to be destroyed by the wreckless Talz.

They successfully infiltrated the base and filled it with explosives. When the battalion had arrived, the base had already been built and the droids were already positioned, so the clones planned an assault. The battalion continued on their original mission.ДЄ 987th Cobalt Battalion Clone Cold Assault Trooper during the Skirmish on Orto Plutonia.ДЇar before the conflict between the 501st and the Talz, the 987th Cobalt Battalion had skirmished across Orto Plutonia after intelligence on Separatist base construction plans. Alpha Company moved into the facility, but the battle had ended. One hundred droids was no match for the deployed clone company, and the victory was well-earned. While Rancor Battalion, 212th and 501st forces combatted the droids inside and around the facility, 987th Cobalt Battalion diverted a hundred droids from the facility, fighting them outside Tipoca City. The Separatists had launched an attack on the cloning facility in an effort to prevent any future cloning. In 22BBY, the 987th Cobalt Battalion were onboard their Venator-class Star Destroyer in the outer rim, when they received a distress call from their home planet: Kamino. In this quick battle, the 987th Cobalt Battalion gained its reputation of swift victories and low fatalities. Then, in a strong final blow, the droids were defeated with ease. While the Separatist Fleet fought a Republic Fleet, the 987th Cobalt Battalion engaged the ground assault, successfully pushing the droid outside the city, and keeping the capital safe. The battalion was alerted of their presence by Reconnaissance Company. Second, Reconnaissance Company were stationed on the perimeter of Theed, while the rest of the battalion waited for the offensive forces to arrive.

First, the civilians, tourists and politicians were evacuated. The 987th Cobalt Battalion were assigned to their first defense mission. Thus, an attack was planned on the peaceful planet of Naboo, in Theed. The incoming Separatist forces did not come as a surprise to the Republic the Confederacy of Independent Systems wanted vengeance against the Grand Army of the Republic because if the victory on Geonosis. The battalion ventured from Alderaan to Jabiim, and used the Cobalt Station as temporary headquarters. The 987th Cobalt Battalion decided to construct their own headquarters on Alderaan for training, storage and recreation. After a few brief battles, the droids were destroyed and the outpost demolished. After defeating the Geonosians, the troopers smeared the dark blue Geonosian blood onto their armor, and nicknamed themselves Cobalt Battalion.ДЄfter the First Battle of Geonosis, the 987th Cobalt Battalion was sent to do reconnaissance and exploration in rural areas of Alderaan, where they discovered a secret Separatist outpost. After the droid army retreated, the 987th Battalion were attacked by hostile Geonosians. They fought for the whole battle, and had few fatalities. The 987th Battalion, unnamed at the time, were deployed to Geonosis under the orders of Jedi Grandmaster Yoda. 3 Known Units Within The 987th Cobalt Battalion.

Clone cold assault trooper