The Mandalorian Civil War represents a clash that took place before the Clone Wars. This conflict arose from a division within the Mandalorian clans, originating from differing beliefs about the Mandalorians' role within the broader galaxy.
This war saw combat between Jaster Mereel's True Mandalorians, under the title of Mand'alor, who championed the idea of Mandalorians functioning as respectable mercenaries, and Tor Vizsla's dissenting group, Death Watch. The Death Watch argued for a reversion to the Mandalorians' more brutal past as raiders and outlaws. The war stretched for more than ten years, with both sides experiencing periods of success and defeat.
Jaster Mereel met his end on Korda Six due to the treachery of a fellow soldier. Following this, Jango Fett took his place as the new Mand'alor and head of the True Mandalorians, a position he held until their disastrous loss at the Battle of Galidraan against the Jedi Order.
At Galidraan, a scheme by Death Watch led a group of Jedi Knights, headed by Master Dooku, to the planet. They were falsely informed that the True Mandalorians were committing acts of murder against civilians. When the Jedi tried to apprehend them, fighting broke out, resulting in the deaths of eleven Jedi and all True Mandalorians present on Galidraan, with the exception of Jango Fett.
In 60 BBY, a Mandalorian warrior of great charisma, Jaster Mereel, rose to become Mand'alor, the leader of all Mandalorian clans. Assuming this role, he started implementing cultural changes, something many had desired since the Ithullan genocide almost 150 years prior. He eventually created a new set of guidelines for Mandalorian conduct known as the Supercommando Codex. He stated that Mandalorians who wanted to fight should simply be well-compensated soldiers and should behave as honorable mercenaries.
However, the Codex and Mereel's changes were not universally accepted. The New Mandalorians, a reformist political group that emerged after a destructive conflict with the Galactic Republic around 678 years before, operated under a separate government from their capital, Sundari, and prioritized pacifism and non-violence.
More concerningly, the followers of the brutal Mandalorian soldier Tor Vizsla had goals that were the opposite of the New Mandalorians. They wanted to return to the ways of the ancient Mandalorians as conquerors and raiders, with the ultimate goal of launching another war of conquest across the galaxy. These skilled but unruly soldiers gathered around Vizsla, forming a splinter group known as the Death Watch. The supercommandos who were loyal to Jaster Mereel rebranded themselves as the "True Mandalorians," and conflict soon broke out between the two groups.
One of the initial battles of the war occurred on Concord Dawn, an agricultural world in the Outer Rim. In 58 BBY, fighting erupted between the Death Watch and the True Mandalorians near the farm owned by the local Fett family.
After a battle that favored the Death Watch, Jaster Mereel and his forces retreated into the Fett farm's fields. While the farm's owner offered sanctuary to the Mandalorians, a vengeful Tor Vizsla tracked Mereel through the fields, where he encountered the farmer's son, Jango Fett. Using the boy as leverage, Vizsla demanded that his father reveal the True Mandalorians' location, brutally assaulting the man when he refused.
When Vizsla threatened to murder the elder Fett in front of his son, Fett's wife tried to save her husband, shooting and killing one of Vizsla's men with a blaster rifle. The Death Watch retaliated, and in the ensuing fight, both of young Jango's parents were killed. However, Mereel and his troops managed to intervene and save Jango's life before retreating back into the crop fields. Vizsla ordered the fields to be set ablaze, attempting to kill Mereel as he fled, but as the fire encircled them, Jango led the True Mandalorians to an irrigation tube that provided them with safety.
Having lost his family—his parents dead and his sister, Arla, captured—Jango decided to join the Mandalorians.
Following their perceived victory over the True Mandalorians, the Death Watch moved into a nearby town, intending to celebrate with a raid before heading to Moonus Mandel. However, the True Mandalorians had regrouped in the town, planning a retaliatory strike. When Vizsla and his men arrived with their armored speeder,
Mereel's second-in-command, Montross, opened fire from an upper-story window, while the other True Mandalorians attacked from sheltered alleys. Death Watch soldiers were felled by blasterfire, while others perished when Jango placed a bomb beneath their speeder. As the True Mandalorians attempted to eliminate their Death Watch enemies,
Jango confronted the man who had murdered his parents, shooting him and avenging his deceased mother and father. Almost all of the Death Watch soldiers were killed in the battle, though Tor Vizsla somehow escaped. As the True Mandalorians prepared to leave the planet, Jango was taken in by Mereel, who raised the boy as if he were his own son.
Despite Vizsla's escape, the True Mandalorians believed that the Death Watch threat had ended after the events on Concord Dawn. However, years later in 52 BBY, the Death Watch proved their continued activity by luring the True Mandalorians into a trap on the planet Korda Six. Hired by the Korda Defense Force, the True Mandalorians traveled to Korda Six to rescue a team of inexperienced security personnel who were pinned down by local hostiles, supposedly poorly equipped and without a formal army.
Upon arriving on the planet in several Meteor-class drop ships, they discovered that the intelligence reports were severely inaccurate and were overwhelmed by superior Kordan forces even before the Death Watch revealed themselves. As Mereel ordered a retreat, the Death Watch soldiers sprung their trap, attacking Jango Fett—now fourteen years old, and considered an adult in Mandalorian culture—and the squad under his command, while Jaster Mereel and Montross were attacked by Vizsla himself.
Mereel was injured in a grenade explosion that Montross avoided using his jetpack. When the injured Mand'alor called for an air lift, Montross abandoned Mereel, leaving him to die on the battlefield, stating that he no longer wanted to follow Mereel's orders. Betrayed and left defenseless, Mereel was killed as Vizsla unleashed laser cannon fire from his four-wheeled tank.
After Mereel's death, Montross returned to the True Mandalorians' landing zone, urging them to obey the Mand'alor's final orders and withdraw. He falsely claimed that Mereel was dead and that Jango had died trying to save him.
However, Fett returned to the landing zone carrying Jaster Mereel's body, exposing Montross as a liar and a traitor. When Montross insisted that Mereel would have wanted him to take command, the other Mandalorians denounced Montross at blaster point and declared that they would only follow Jango, Jaster Mereel's chosen successor. Montross was reluctantly allowed to leave, disappearing into exile, while Jango became the new Mand'alor and leader of the True Mandalorians.
In the years following the Battle of Korda Six and leading up to 44 BBY, the True Mandalorians achieved a significant victory that severely weakened the Death Watch. However, instead of admitting defeat, Vizsla sought refuge with the Governor of Galidraan and his assistance in rebuilding the Death Watch. Following Vizsla's plan, the governor hired the True Mandalorians to suppress a local uprising.
The True Mandalorians went to Galidraan, where they dealt with the rebels. After completing their mission, Jango went to the governor's estate to collect their payment. Jango had also learned of the governor's involvement with the Death Watch and demanded to know Vizsla's location.
At that moment, Vizsla revealed himself in the castle and attacked Jango with a group of Death Watch soldiers, forcing him to escape through a large window. By then, the governor had already contacted the Jedi Council requesting aid, claiming that the Mandalorians were murdering "political activists" as well as innocent women and children.
To address the governor's concerns about the lack of evidence, Vizsla assured him that his own men would provide the necessary body count.
Jango hurried back to the True Mandalorians' base camp, desperately trying to comm his second-in-command, Myles, to warn him about the approaching Jedi ships he had spotted, but he arrived at the same time as a Jedi strike team led by Jedi Master Dooku.
The Jedi had taken the Galidraan governor at his word and ordered the True Mandalorians to surrender on charges of suspected murder. Dooku's Padawan, Komari Vosa, added that they would be killed if they resisted.
Innocent of the charges and indignant toward the Jedi, Jango ordered his troops to open fire, specifically ordering them to target Vosa. Their blasters quickly proved ineffective against the Jedi's lightsabers, and Jango called for the use of projectiles and air cover via jetpacks. Myles tried to provide air support but was killed midair by one of the Jedi while Jango watched helplessly.
During the battle, Jango personally killed six Jedi—including the one who killed Myles—using only his hands, feet, and armored body. However, his actions were not enough to change the outcome. Eleven Jedi died in the battle, but Silas and Jango were the only True Mandalorian soldiers to survive. Jango was eventually subdued by the Jedi and handed over to the custody of Galidraan's governor, who stripped him of his armor and sold him into slavery.
After spending several years in servitude aboard a spice transport, Jango managed to escape, retrieve his Mandalorian armor from the Governor of Galidraan, and track Vizsla's ship to Corellia. There, he killed Vizsla after a long fight, avenging the True Mandalorians and delivering the final blow of the war. The remaining Death Watch members scattered, disappearing from the galaxy until the Clone Wars, when, with the True Mandalorians gone and Jango Fett dead, they turned their attention to the pacifistic New Mandalorians.
The Mandalorian Civil War was fought over ideology, concerning how the Mandalorians would behave in the future, and was described by some as a battle for the very essence of the Mandalorians. Although the Death Watch succeeded in destroying their True Mandalorian enemies, Jaster Mereel's Supercommando Codex lived on under his adopted son Jango's leadership as Mand'alor and for generations afterward.
Despite its philosophical and ideological importance, the war was fought between relatively small factions and was viewed by some as little more than a typical power struggle. Mandalore's standing army was consumed by the conflict, along with several prominent clans, but it barely affected Mandalorians living off-world, even those in the Mandalore sector.
After the war, Jango Fett, scarred by the loss of his True Mandalorian comrades and his years as a slave, distanced himself from the rest of his people and his role as Mand'alor. He turned to the solitary life of a bounty hunter until his death at the First Battle of Geonosis.