The Yinchorri Uprising, alternatively referred to as the Yinchorri Crisis, was a period of intense aggression initiated by the Yinchorri around 33 BBY. Having integrated into the Galactic Republic circa 58 BBY, the Yinchorri quickly adopted new technologies and trade practices. They rapidly developed a strong military, fueled by desires for territorial expansion. Incited by Darth Plagueis and Darth Sidious, with assistance from Vilmarh Grahrk, the Yinchorri first took control of the Golden Nyss Shipyards and then launched an invasion of Mayvitch 7, a nearby moon. Plagueis's underlying motive was to assess the Yinchorri's suitability as hosts for a secret cloned army intended to destroy the Jedi.
The Jedi Order dispatched a diplomatic mission to investigate the situation, but the two Jedi representatives were murdered. Consequently, the Order sent a larger force, composed of both Jedi Masters and Jedi Knights, who were immediately ambushed upon their arrival in the Yinchorri system. Following a series of fierce battles across Yitheeth, Yibikkoror, and their home planet of Yinchorr, the Jedi, supported by the Judicial Forces, managed to subdue the Yinchorri during the pivotal Battle of Uhanayih. Subsequently, the Republic imposed an interdict on Yinchorr.
The Sith achieved a threefold victory. Firstly, seven Jedi, including a member of the Jedi Council, were killed. Secondly, the Yinchorri, being aggressive, expansionist, equipped with cortosis, and resistant to mind tricks, posed a potential obstacle to his plans for ruling the galaxy. Sidious skillfully manipulated events to have others eliminate this threat for him. Thirdly, the political influence of Supreme Chancellor Finis Valorum within the Galactic Senate was significantly weakened, thereby facilitating Senator Palpatine's ascension to power.
The Yinchorri were a formidable reptilian species native to the planet Yinchorr located in the Expansion Region. Their society was structured into two distinct castes: an intellectual ruling class and a warrior class. Having developed interstellar travel capabilities in the final decades of the Galactic Republic, they had colonized several planets and moons within their star system, including Yitheeth, Yibikkoror, and Uhanayih. The core of Yinchorri culture was encapsulated in the principle of "might makes right," which asserted that anything they could seize and maintain through force was rightfully theirs.
Around 500 BBY, the Galactic Republic first made records of Yinchorr. By 58 BBY, the Yinchorri had become integrated as full members of the Galactic Republic, gaining representation in the Galactic Senate. Driven by a strong militaristic and expansionist mindset, they began acquiring advanced technologies such as hyperdrive-equipped spacecraft, sophisticated weaponry, and lightsaber-resistant cortosis shields. Around 33 BBY, the Sith Lord Darth Sidious conspired with the Devaronian mercenaries Vilmarh and Holmar to exploit these circumstances for his own purposes.
Vilmarh served as an intermediary between the Sith and the Yinchorri, negotiating with the Yinchorri Council of Elders, including Sothek, Jorek, and Kardek. They agreed to orchestrate a raid on the Golden Nyss Shipyards in order to obtain war materials. Kardek even proposed a marital alliance between Grahrk and his daughter Vooma. Vilmarh successfully fueled fear and hatred towards the Jedi Order, the Republic's ancient protectors and adversaries of the Sith.
Considering their aggressive militarism, Sidious viewed them as a potential threat to his plan for galactic domination. He also aimed to weaken the Jedi Order by drawing its members into the conflict, thereby eliminating several Jedi. Furthermore, he intended to use the outbreak of war to undermine the government of Supreme Chancellor Finis Valorum, thus clearing the path for his own rise to power.
Working in conjunction with the Grahrks and their Sith master, the Council of Elders organized a raid on the nearby Golden Nyss Shipyards to secure a number of attack ships and starfighters for their planned military offensive. Vilmarh successfully smuggled in a contingent of Yinchorri troops and deceived the shipyard master, Gzin. After achieving their objectives and destroying the shipyards, the Yinchorri initiated their main offensive.
Utilizing their newly acquired war fleet, they launched attacks on several surrounding non-Yinchorri worlds, including Mayvitch 7, a moon of the planet Amador within the Chalenor system. This moon had been colonized by Human settlers from Immalia to protect their mining operations from pirates. The Yinchorri quickly overwhelmed the moon's defenses and eliminated all resistance.
A Mayvitch soldier managed to contact the Jedi Temple on Coruscant and alert them to the danger posed by the Yinchorri. However, this message only reached the Jedi Temple four standard days later. By that time, the Yinchorri had seized control of the Chalenor system and several key planets. Upon receiving news of the events on Mayvitch 7, the Galactic Senate, via Chancellor Valorum, requested that Jedi Master Mace Windu dispatch a Jedi team to the Yinchorr system to conduct an investigation.
Without consulting the Council, Windu sent Jedi Knight Naeshahn and her Padawan, Ebor Taulk. Due to inadequate intelligence, the pair were unaware of the Yinchorri's resistance to mind tricks, their cortosis weaponry, and their aggressive militarism. The mission resulted in failure, and the Jedi were killed, with their mutilated bodies left on Valorum's Coruscant doorstep.
As a response, the Jedi Order sent a second, larger mission to the Yinchorri system to investigate the reports of Yinchorri aggression against neighboring systems. The Jedi mission consisted of twelve Jedi, divided into three groups, each assigned a Consular-class cruiser because there were only three habitable worlds in the Yinchorri system.
Mace Windu, Saesee Tiin, Qui-Gon Jinn, and his Padawan Obi-Wan Kenobi were assigned to the harsh Yinchorri homeworld of Yinchorr, while Adi Gallia, Eeth Koth, Tsui Choi, and Theen Fida were assigned to the ocean world of Yitheeth. Plo Koon, Micah Giiett, Lilit Twoseas, and K'Kruhk were sent to Yibikkoror, a tiny world with a dense atmosphere. All three groups would search for a rumored Yinchorri command center.
Upon exiting hyperspace in the Yinchorri system, they were immediately attacked by Yinchorri starfighters. The Jedi were at a disadvantage because their cruisers were unarmed. However, during the engagement, Gallia's cruiser managed to destroy two fighters by tricking a third into destroying them before proceeding to Yitheeth.
Meanwhile, Windu's cruiser had its shields disabled by an enemy fighter. However, they avoided destruction due to Tiin's actions, who made a jump into hyperspace past a planet. To their Yinchorri pursuers, it appeared that their target had made a jump into hyperspace through the planet. By the time they found out, it was too late since the cruiser had headed to Yinchorr.
However, Giiett's cruiser failed to shake off their Yinchorri pursuers. K'Kruhk then proposed to the other Jedi that they trick the Yinchorri into thinking that they had left the cruiser by releasing all the escape pods and the salon pod. The plan worked perfectly, and the Yinchorri fighters went after them, allowing the cruiser to evade them and land at a floating platform on gassy Yibikkoror. The Jedi barely escaped their Yinchorri pursuers, though they all managed to reach their destinations.
In collaboration with the Sith Lords and Vilmarh Grahrk, the Yinchorri planned to launch an attack on the Jedi Temple on Coruscant with a commando force of warriors. Following the dispatch of a task force of Jedi to the Yinchorri system to investigate reports of Yinchorri aggression, reports came of their encounter with Yinchorri forces during a briefing of the Jedi Council. However, the messages were confusing and contradictory. Master Yoda also sensed danger was coming through the Force.
As a result, the Jedi made preparations including evacuating the younglings from their quarters and being on active alert. Outside the outskirts of the Temple, the Yinchorri were indeed in position and ready for attack. Their actions were being observed by Darth Maul who informed his master Darth Sidious. The Jedi Jude Rozess was on guard duty when she was suddenly attacked by a Yinchorri donning a flutter-pack. Despite being overpowered and strangled by a Yinchorri, she managed to reactivate her lightsaber; taking him down with her.
Back in the Temple, the Yinchorri task force found that all the sleeping quarters were empty. The troops then entered a chamber where they were met by a large group of armed Jedi, including Yoda. In the end, almost all the Yinchorri were killed while only two Jedi died: Jude Rozess and Tieren Nie-Tan.
Yoda interrogated the last remaining Yinchorri and asked him the location of the Yinchorri high command. The soldier responded to the Jedi Master by telling him that he did not know since he was only an ordinary soldier. Yoda then turned to converse with Soon Bayts, a Jedi Knight who brought word on the whereabouts of the Jedi in the Yinchorri system.
This distraction gave the Yinchorri in the Temple enough time to grab his weapon and attempt to shoot the Jedi. Yoda threw him against a wall, presumably killing him. The Jedi then came to the conclusion that the Yinchorri were misguided rather than bloodthirsty and that the attack may have been the work of an unknown party, rather than the Yinchorri themselves.
In the Yinchorri System, the Jedi teams landed at their respective destinations and fanned out to find the hidden Yinchorri command center. Gallia's team landed on the ocean moon of Yitheeth. Posing as traders looking to buy a fictitious T-21 hyper particle exchange chamber, the four Jedi set off for a nearby settlement on a speeder provided with the cruiser.
They soon came under attack by a group of Yinchorri under the command of Vilmarh's nephew, Olmar Grahrk. However, the Jedi fought back and defeated their Yinchorri attackers. They then took Grahrk captive, who told them that the Yinchorri high command was not on Yitheeth. Gallia then decided to leave for nearby Yibikkoror to aid fellow Masters Koon and Giiett, who were also under attack after their crash landing.
Outnumbered, Giiett requested assistance from Gallia's team. The Kel Dor Jedi Koon then suggested to his companions that they traverse through the dense atmosphere on the floating platform. Their Yinchorri pursuers followed them and one fell into the dense sea of gas below, presumably killing him. Knowing that they could not rely on Gallia to arrive in time, the Jedi attempted to climb to the top of the platform which was held up by balloons.
Having reached the top, they were attacked by more Yinchorri wearing flutter-packs, though the Jedi managed to fight them off until the arrival of Gallia's cruiser. The cruiser was too large to land on the platform, which was swarmed with throngs of hostile Yinchorri. Thus, the four Jedi detached a balloon in their attempt to reach the cruiser.
All four Jedi gripping the balloon's single cable, they floated upward, still under fire from their pursuers. Having reached the ship's docking rig, they were greeted by the Zabrak Jedi Master Koth who managed to get them all inside. Before Master Giiett could get inside, he came under attack from more airborne Yinchorri. Giiett then grabbed the balloon and made another jump away from the ship while the cruiser moved downwards to allow him to descend down the docking rig, evading his attackers. Having barely escaped, the Jedi traveled to Yinchorr to assist Windu and Qui-Gon's team.
In the meantime, Mace Windu's team landed on arid Yinchorr to search for a rumored Yinchorri high command. After landing, Qui-Gon and Kenobi went on a scouting mission to search for the command. Instead, they discovered that the Yinchorri were mustering their military. Barely escaping the Yinchorri, the two Jedi arrived back at the temporary base and informed Windu and Tiin of their findings.
Qui-Gon related to them that they had discovered a military staging area for an invasion outside the walls of a city. During the debriefing, their cruiser blew up, signalling that the Yinchorri had found their ship. To calm his companions down, Windu assured them that Adi Gallia and the other Jedi reinforcement would soon arrive. The Jedi were quickly surrounded by a Yinchorri army equipped with flutter-packs and tanks.
Luckily for them, the other eight Jedi arrived on the remaining Consular-class space cruiser and joined the fight. Five of these reinforcements formed a wedge and fought through the Yinchorri lines, diverting the attacks on Mace Windu's team and allowing his team to come to their aid in return, thus attacking the Yinchorri on two fronts. He then ordered his companions to link up with the other five Jedi.
On the way, Saesee Tiin confronted an enemy tank and killed the driver with his lightsaber before leaping to safety. Meanwhile, the cruiser came under attack by more Yinchorri forces, including a tank. Amidst a vicious battle with the Yinchorri, the Jedi attempted to get back to their cruiser. During the process, Lilit was wounded while trying to protect her Padawan K'Kruhk.
However, when they reached the cruiser, they found that it had been attacked. All the Yinchorri had been killed along with Padawan Theen Fida. Mace Windu then instructed his fellow Jedi to set their grief aside since they had to succeed in their mission to locate the Yinchorri high command. Lilit would later die of her wounds.
He also ordered Saesee Tiin to prepare the cruiser for takeoff and to see if he could get a transmission through to Master Yoda at the Jedi Temple. Having entered the ship, they found that Grahrk had freed himself and was at the controls, attempting to communicate with someone, not realizing that this other person was Darth Sidious. After restraining Grahrk, they were able to transmit their findings to the Jedi Council.
Meanwhile on Coruscant, Master Yaddle revealed to the others that she had consulted the holocron of Master Tharence Wo and learned of the existence of a fourth moon in the system. It was little more than a barren rocky world known as Uhanayih, which meant "Within World" in the Yinchorri. Windu then sent another transmission to the Jedi Temple with intelligence that the hidden command center had been located on a lifeless rocky planetoid close to the system's star. He told his fellow Jedi to inform Valorum of this information.
Back on the battlefield, Micah Giiett was shot in the back by a Yinchorri warrior. Dying, he told his companions to leave him behind, propped against a wrecked tank, and to continue their mission at all costs. As soon as his companions had left, Micah was surrounded by a squad of Yinchorri. He told them to come closer on the pretext of revealing "Jedi secrets" to them.
When they did, he told them that the Jedi were not afraid to make a worthy stand before activating his lightsaber and igniting the tank's fuel cells, presumably killing them all and dying in the process, with his death being transmitted by the Force and felt by his Jedi companions all over the galaxy. Even Darth Sidious himself felt it in the Force. The Dark Lord then ordered Darth Maul to retrieve Vilmarh Grahrk.
Back on Coruscant, Valorum began negotiating for a trade and technological embargo on the system with other senators. Due to the influence of both Sidious's dark side powers and political machinations, the deliberations took much longer than either Valorum or the Jedi expected. After calling in every favor Valorum was owed since 38 BBY and making concessions to a group of leading senators (including Tikkes, Onaconda Farr, and Yarua), Valorum managed to get the Senate to vote to approve the sanctions.
He also mustered enough support to dispatch four Judicial Forces attack groups to the Yinchorr system to aid the Jedi and end the uprising. Meanwhile, the surviving Jedi disembarked Yinchorr on their cruiser and traveled to Uhanayih to seek out the Yinchorri command center. Having arrived at Uhanayih, their unarmed cruiser was attacked by a massive Yinchorri fleet. Luckily for the Jedi, help came in the form of a Republic reinforcements consisting of light assault cruisers and armed CSS-1 Corellian Star Shuttles.
Soon, much of the Yinchorri fleet had been destroyed or immobilized, allowing the Jedi to make their way to Uhanayih. Windu then ordered Qui-Gon to contact the Admiral in charge of the Republic forces and request for an escort for their trip to the Yinchorri high command. Thus, the Jedi cruiser approached the moon with the escort and entered a huge tunnel which led to the Yinchorri base.
Having arrived and seeing no place to land, the Jedi cruiser crash-landed into the high command's war room before the defending Yinchorri could close its blast shutters. Meanwhile, in the war room, one of the Yinchorri remarked to his companion that the Vilmarh had assured that the Republic would not intervene. His friend then replied that Vilmarh and his men had fled and then ordered the blast shutters to be shut. However, it was too late.
The cruiser wrecked the war room, causing heavy damage to the Yinchorri. The commander begged the victorious Jedi not to kill them. Windu replied by remarking that those Yinchorri were responsible for the chaos and then asked Gallia about what Master Oppo Rancisis said about the philosophy of "might makes right". Gallia replied by telling him that that philosophy is "often recanted" upon encountering a more powerful foe.
Having been defeated by the Jedi and the Republic forces, the Yinchorri commanders communicated their capitulation, thus ending all combat operations. The Yinchorri system was then subjected to an interdict and placed under quarantine by the Republic Navy, cutting off all travel both to and from the system. Evidence recovered from both Holgrath and Yinchorri sources pointed to the involvement of the Devaronian Vilmarh Grahrk in the conspiracy. However, Master Yoda observed that the Yinchorri were simply instruments in a much grander scheme.
The Jedi who survived the conflict returned to their Temple located on Coruscant, bearing the remains of their fallen comrades, arriving to a mournful gathering. After a period of debriefing, the Jedi Council selected the Cerean Jedi Knight Ki-Adi-Mundi to fill the vacancy left by the deceased Giiett. After careful consideration of all the facts, Yoda determined that Vilmarh, the fugitive, did not possess the necessary incentives to instigate the Yinchorri, suggesting he was collaborating with an unidentified accomplice.
Looking at the bigger picture, the Yinchorri Uprising played a role in Darth Sidious's strategy for galactic dominance. First, it weakened the Jedi Order by killing seven Jedi, including a member of the Jedi Council. Second, it eliminated the Yinchorri as a potential problem for his plans, at least temporarily. Their inherent aggression, expansionist tendencies, usage of cortosis, and resistance to mind manipulation would have made them a significant obstacle to his New Order.
Politically, the uprising damaged Chancellor Valorum's standing and opened the door for Senator Palpatine to ascend to power. His culpability in the Jedi deaths during the uprising, the slow response from the Senate, and the depletion of his political influence in enacting the Act led to Valorum's administration becoming ineffective. As a result, this incident was the initial step down the path that led to his removal from office the following year during the Invasion of Naboo by the Trade Federation.
During the time of the Empire, the Yinchorri would once again attract the attention of Sidious, now the Emperor. Around 3 ABY, the Imperial Governor Marcellin Wessel took their Council of Elders hostage, demanding that they deliver the Rebel leader Leia Organa into the custody of the Empire. Ultimately, the Empire executed the Council, prompting the Yinchorri to launch a rebellion.
As a reprisal, the Empire inflicted severe damage on Yinchorr, including the destruction of its primary city, Tol-Kachorn. Palpatine later established the Imperial Royal Guard Academy on this remote, devastated planet. The planet's harsh desert environment proved ideal for the training of these elite guards. After the New Republic liberated the planet, the Yinchorri started the process of rebuilding their society, but they chose not to rejoin the galactic community.