The Mimban Campaign, also known as the Battle of Mimban or Occupation of Mimban, was a planetary war between the Galactic Empire and Mimbanese Liberation Army in 10 BBY during the early years of the Imperial Era on the swamp world of Mimban in an effort to secure the planet's vital resources while establishing a regime loyal to the Empire. The 224th Imperial Armored Division engaged the Mimbanese Liberation Army, with the latter eager to drive the Imperials from their homeworld at all costs. The campaign saw the deployment of numerous swamp troopers and wet-weather gear stormtroopers, with the Imperial ground forces making use of trench warfare against the native Mimbanese.
The planet Mimban was a backwater Expansion Region that was home to several species including the Mimbanese. The planet was rich in hyperbaride minerals, making it the target of energy mining interests and various governments including the Confederacy of Independent Systems, the Galactic Republic, and the Galactic Empire. The Confederacy's mining devastated the world's environment.
During the Clone Wars, Mimban was invaded by the Confederacy military. The indigenous Mimbanese Liberation Army resisted the Separatist forces with aid from the Galactic Republic. Members of the Grand Army of the Republic's 224th Division, known as the mud-jumpers, fought alongside the Mimbanese, promising the species freedom once the Separatists were defeated. Following the transformation of the Republic into the Galactic Empire in 19 BBY, the Empire sought to exploit Mimban for its mineral resources in order to fuel the Imperial war machine despite the ecological devastation its mining caused, like that of the Confederacy before it.
The Empire's activity on Mimban had started conflict by the time Cassian Jeron Andor was sixteen years old. Andor was conscripted into the armed forces during his time in prison. He was immediately deployed to Mimban and participated in six months of fighting, although technically he was only the unit's cook. Andor himself, however, would claim he saw active combat. Under the orders of Grand Moff Wilhuff Tarkin, Moff Bin Essada of the Circarpous sector sought to procure the abundant natural resources that existed on the swampy world. The Imperials encountered resistance from their former Mimbanese allies as they attempted to occupy Mimban.
Around 10 BBY, the 224th Imperial Armored Division, consisting of both Imperial Army Swamp troopers and wet-weather gear stormtroopers, was deployed to Mimban. The 224th Armored Division established a temporary headquarters called Imperial Forward Field Operations inside the disputed wilderness zone. The Division was locked into trench warfare against the Mimbanese Liberation Army, which used guerrilla tactics including improvised mines, tripwires, and catapults against Imperial forces and vehicles.
In one of the bloodiest battles of the campaign, known simply as the battle on Mimban, Major Staz led a group of Swamp troopers including Corporal Han Solo in a ground assault to capture a ridge from the Mimbanese. The Mimbanese fired explosives which killed Major Staz. 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, the last senior officer in the group. Beckett led the Swamp troopers in a successful assault on the ridge.
Following the skirmish, Lieutenant Alayus Bolandin told Solo and his comrades that they would be departing within three hours to the Southern Marshlands. He also requested volunteers for an advance party. When Solo questioned what the Empire was doing to Mimban and suggested that the Imperials were the aggressors, Bolandin regarded Solo as a troublemaker.
During a break in the fighting, Solo encountered "Captain" Beckett and his gang associates Val and Rio Durant, whom he ascertained were smugglers dressed in stolen Imperial uniforms. The criminals were planning to commandeer a Y-45 armored transport hauler. Recognizing this as an opportunity to leave behind his life as a mere grunt, Solo initially attempted to persuade Beckett into allowing him into the group, offering his services as a pilot.
When Beckett and his gang rebuffed Solo, he threatened to expose them as infiltrators. However, Beckett turned the tables on Solo by convincing Lieutenant Bolandin that they had caught Solo trying to desert the Imperial Army. Seeking to rid the unit of a troublemaker, Bolandin threw Solo into a pit to be devoured by "the beast," a Wookiee Chewbacca. Chewbacca had been betrayed by a bounty hunter who handed him over to Imperial forces on Mimban.
While Chewbacca was initially hostile to Solo, Solo managed to use his knowledge of Shyriiwook and quick wit to convince the Wookiee to help him escape the pen. After breaking out, Solo convinced Chewbacca to come with him to a nearby airfield where Beckett and his gang were preparing to depart on their stolen transport hauler. Impressed by the young man's determination, Beckett allowed both Solo and Chewbacca aboard his stolen AT-hauler.
After suffering injuries that ended his career as a TIE fighter pilot, Beilert Valance was reassigned to the Imperial Army, which he served in as a stormtrooper and also a regular army soldier. Sent into Mimban campaign as a swamp trooper, he and his unit saw action in a trench. Valance attempted to call for air support. When the other soldiers doubted that Imperial reinforcements would come for them, Valance was determined to complete his mission and led his men out of the trench. As a result, Valance suffered life changing 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 first appeared in the 2018 film Solo: A Star Wars Story.