A military operation that took place on the world of Zaloriis was the first time a new type of All Terrain Armored Transport was used in combat. This new model had been secretly developed and built on Zaloriis by Colonel Maximilian Veers at the time.
Following the Battle of Yavin, the people of Zaloriis grew increasingly dissatisfied with the Imperial presence, especially the strange experiments with walking machines being conducted by the Imperial military. Darth Vader was summoned to a meeting with the Zaloriis Minister Transe Decar, but it was a trap. The rebellious Minister had his troops capture Vader's men and hold him hostage. The Dark Lord quickly killed all the Zaloriis militia members present. He then interrogated a soldier to find out where the captured Imperials were being held. After learning the location of the detention compound, he and his Stormtrooper squad went there and freed the troops.
After regrouping and gathering information, Vader discovered that Colonel Veers had been captured by the local militia and was going to be executed. Vader and his troops ambushed the prison convoy, which consisted of two mounted troopers and six Zaloriis militiamen, and freed the Colonel. They also recruited several heavy mounted troopers. Veers informed Vader that Fondor II was under attack, so Vader went to the city of Fondor II, where they were able to call for reinforcements after eliminating some Rebels.
Vader then assigned some Banthas he and his forces gained on the way over to one of the camp's nurseries.
To gain an edge in the upcoming battle, the decision was made to retrieve the prototype AT-AT walker from the research facility at Camp Culroon. After getting the walker, Blizzard 1, Vader also gained control of five heavy Dewback troopers, five repeater troopers, two AT-PTs, two AT-STs, two AT-AAs, and five workers, as well as supplies of food, ore, carbon, and nova crystals. The Galactic Emperor Palpatine contacted Darth Vader and ordered him to use his forces to conquer Zaloriis City as punishment for its betrayal. Veers suggested moving Blizzard 1 to Fondor II, and one worker was ordered to stay behind to create a carbon processing center in Culroon. Later, Vader had a missile trooper and a worker stop at an ore crystal field to build a command center and some prefab shelters. Two repeater troopers were also stationed near the construction site to watch for Rebels. Additionally, some mounted troopers and Mobile proton torpedo launchers ambushed the convoy and tried to destroy Blizzard 1, but the escorts easily drove them off. Upon reaching Fondor II, Blizzard 1 was placed in its hangar to be armed and prepared for battle.
Several Rebel soldiers were sent from Zaloriis City to attack an area near the oasis, but turrets kept them at bay. Vader then sent workers to mine for nova crystals, carbon, and ore near his landing site. Afterwards, Vader took advantage of the Rebels' weakened defenses, caused by the desert turret keeping their forces occupied, and sent three heavy energy pummels and three heavy artillery platforms to overwhelm the Rebel army. A squad of ten repeater troopers and five anti-air troopers were also sent to support them. The heavy artillery platforms then destroyed the turrets guarding Zaloriis City. As a last resort, the Rebels inside sent out X-wings and Y-wings to attack the advancing Imperial forces, but many were shot down by the missile troopers. The artillery weakened the walls enough for the pummels to break them down. Vader then ordered Veers to test-drive Blizzard 1 on the city.
Two Rebel fortresses had been built with the help of the Zaloriis government, and they would be the main targets of the attack. The AT-AT prototype played a major role in the assault, impressing the Imperial commanders and discouraging the Zaloran rebels. During the height of the battle, Zaloriis City was heavily damaged by Imperial weapons, especially those on Blizzard 1.
The Battle of Zaloriis was first mentioned in the strategy guide for the 2001 video game Star Wars: Galactic Battlegrounds during the Darth Vader campaign. The mission, and therefore the battle, was also included in the game's 2002 expansion pack, Clone Campaigns.