Commander Keller, a clone trooper of the Galactic Republic, commanded a squad composed of both standard clones and specialized Galactic Marines. This squad operated on the icy world of Toola amidst the Clone Wars, a conflict between the Republic and the Confederacy of Independent Systems.
In the year 19 BBY, close to the conclusion of the Clone Wars, Keller's squad participated in an attack targeting the primary power sources of the Confederacy on Toola. This operation was overseen by Jedi Generals Simms and Kai Hudorra, along with Jedi Commander Noirah Na. However, the [Great Jedi Purge](/article/great_jedi_purge/legends] began during this assault. Supreme Chancellor Palpatine, secretly the Sith Lord Darth Sidious, initiated Order 66, which compelled the clone troopers to betray and eliminate their Jedi superiors. Keller's unit successfully eliminated Jedi Master Simms but failed to capture the two remaining Jedi.
As the Outer Rim Sieges commenced, Keller's unit received deployment orders to the frozen planet of Toola, where they were tasked with engaging the stationed CIS forces. After a prolonged period of stalemate against the Separatist forces, Jedi General Kai Hudorra, Jedi General Simms, and Hudorra's Padawan initiated an offensive against the droid army's main generators, utilizing a small contingent of the unit while the remaining clones executed a diversionary maneuver.
Their strategy proved effective, but shortly afterward, Commander Keller received the directive to enact Order 66, leading the clones to turn their weapons against their Jedi leaders. While they successfully eliminated Jedi Master Simms, Kai Hudorra and his padawan managed to escape using Single Trooper Aerial Platforms.
Soon after, Keller and his unit located the two Jedi at Ithaqua Station, a small civilian spaceport on Toola. Upon arriving at the station, Keller and his troops commenced a search for the elusive Jedi, conducting raids on various locations and demanding identification from the inhabitants. Eventually, they reached a small cantina where Hudorra was present, prompting Keller and two of his men to initiate a search for the Jedi. Unfortunately for them, the cantina patrons, having been persuaded by Kai to oppose the clones, launched an attack against them.
Keller's unit continued their search of Ithaqua Station, but they were ultimately unsuccessful in capturing the two Jedi, who managed to escape on a transport destined for Coruscant.
The clone troopers serving in Keller's unit were equipped with both standard phase II clone trooper armor and white Galactic Marine armor. Some troopers within the unit also displayed yellow markings on their shoulder pauldrons. Their standard weaponry consisted of DC-15A blaster rifles and DC-15S blaster carbines. During their deployment on Toola, select members of the unit utilized Mastmots fitted with twin laser turrets mounted on either side.