The Mimban Campaign, alternatively referred to as the Battle of Mimban or the Occupation of Mimban, represented a planetary conflict. This war saw the Galactic Empire clashing with the Mimbanese Liberation Army in 10 BBY, during the initial years of the Imperial Era. The setting was the swamp planet of Mimban, where the Empire aimed to secure essential resources and establish a government loyal to its cause. The 224th Imperial Armored Division was pitted against the Mimbanese Liberation Army, the latter determined to expel the Imperials from their homeworld at any cost. The campaign involved the deployment of numerous swamp troopers along with wet-weather gear stormtroopers, with the Imperial ground forces utilizing trench warfare tactics against the native Mimbanese.
Mimban, a remote world located in the Expansion Region, served as the home for various species, most notably the Mimbanese. It was a planet abundant in hyperbaride minerals, making it a target for energy mining corporations and multiple governing bodies, including the Confederacy of Independent Systems, the Galactic Republic, and ultimately, the Galactic Empire. The mining operations conducted by the Confederacy resulted in significant environmental damage to the planet.
During the Clone Wars, Mimban was invaded by the Confederacy military. The local Mimbanese Liberation Army actively resisted the Separatist forces, receiving assistance from the Galactic Republic. Soldiers from the Grand Army of the Republic's 224th Division, known as the mud-jumpers, joined forces with the Mimbanese, promising them freedom upon the Separatists' defeat. After the Republic transformed into the Galactic Empire in 19 BBY, the Empire aimed to exploit Mimban's mineral wealth to support its war efforts, heedless of the environmental destruction caused by its mining activities, much like the Confederacy before it.
By the time Cassian Jeron Andor reached the age of sixteen, the Empire's presence on Mimban had already sparked conflict. Andor was drafted into the armed forces while incarcerated. He was promptly dispatched to Mimban, participating in six months of combat, despite officially being assigned as the unit's cook. Andor would later assert that he engaged in active combat. Under the directives of Grand Moff Wilhuff Tarkin, Moff Bin Essada of the Circarpous sector sought to acquire the abundant natural resources found on the swampy world. As the Imperials attempted to occupy Mimban, they faced resistance from their former Mimbanese allies.
Around 10 BBY, the 224th Imperial Armored Division, which included both Imperial Army Swamp troopers and wet-weather gear stormtroopers, was sent to Mimban. The 224th Armored Division established a provisional headquarters known as Imperial Forward Field Operations within the contested wilderness area. The Division became entrenched in trench warfare against the Mimbanese Liberation Army, which employed guerrilla tactics such as improvised mines, tripwires, and catapults against Imperial forces and vehicles.
During one of the campaign's most brutal engagements, simply known as the battle on Mimban, Major Staz commanded a group of Swamp troopers, including Corporal Han Solo, in a ground offensive to seize a ridge from the Mimbanese. The Mimbanese deployed explosives, resulting in Major Staz's death. Han and several soldiers including Corporal Danith Nodar, Private Collum Woslo, Corporal Sharlu Greslin, Corporal Wesger Odry, Medic Gorji Sandem, Private Bokret Humphreys, Specialist Gillen Finders, Sergeant Mattiso Trodu, and Corporal Chakobi Sanwright regrouped in a trench under the command of "Captain" Tobias Beckett, who was the highest-ranking officer remaining in the group. Beckett led the Swamp troopers in a successful assault on the ridge.
After the skirmish, Lieutenant Alayus Bolandin informed Solo and his fellow soldiers that they would be departing for the Southern Marshlands within three hours. He also asked for volunteers for an advance team. When Solo questioned the Empire's actions on Mimban, implying that the Imperials were the aggressors, Bolandin viewed Solo as a troublemaker.
During a lull in the fighting, Solo encountered "Captain" Beckett and his gang associates Val and Rio Durant, whom he recognized as smugglers disguised in stolen Imperial uniforms. The criminals were planning to seize a Y-45 armored transport hauler. Seeing this as an opportunity to escape his life as an ordinary soldier, Solo initially attempted to persuade Beckett to let him join the group, offering his skills as a pilot.
When Beckett and his gang rejected Solo, he threatened to expose them as infiltrators. However, Beckett outmaneuvered Solo by convincing Lieutenant Bolandin that they had caught Solo attempting to desert the Imperial Army. Seeking to get rid of a disruptive element, Bolandin threw Solo into a pit to be devoured by "the beast," a Wookiee named Chewbacca. Chewbacca had been betrayed by a bounty hunter who turned him over to Imperial forces on Mimban.
Although Chewbacca was initially hostile towards Solo, Solo used his knowledge of Shyriiwook and his quick thinking to persuade the Wookiee to help him escape the enclosure. After breaking free, Solo convinced Chewbacca to accompany him to a nearby airfield where Beckett and his gang were preparing to leave on their stolen transport hauler. Impressed by the young man's resolve, Beckett allowed both Solo and Chewbacca to board his stolen AT-hauler.
Following injuries that ended his career as an TIE fighter pilot, Beilert Valance was reassigned to the Imperial Army, where he served as both a stormtrooper and a regular army soldier. Deployed to the Mimban campaign as a swamp trooper, he and his unit experienced combat in a trench. Valance attempted to request air support. When the other soldiers doubted that Imperial reinforcements would arrive, Valance remained determined to complete his mission and led his men out of the trench. As a result, Valance suffered life-altering injuries, including the loss of the left side of his face and his remaining arms and leg. After being discharged from the Imperial Military, Valance became a bounty hunter who worked for the Hidden Hand crime syndicate and later the Rebel Alliance.
The Mimban campaign made its first appearance in the 2018 film Solo: A Star Wars Story.