The Massassi Group, also known as the Massassi unit, was considered to be one of the largest rebel cells that fought against the Galactic Empire in the years prior to the Battle of Yavin. Aligned with a rebel network, this rebel cell had many members and was led by General Jan Dodonna. The unit was based at the Great Temple on Yavin 4. Eventually the Massassi group, along with other rebel cells, would organize and become the Alliance to Restore the Republic and its base grew to be the Rebel Alliance's main hidden fortress. The unit was instrumental in the battles of Scarif and Yavin, in the latter of which it was able to destroy the Death Star battle station.
General Jan Dodonna, a former bridge officer on a Venator-class Star Destroyer during the Clone Wars, became disillusioned with the Galactic Empire and defected to the growing rebellion, a loose collection of rebel cells secretly coordinated by Imperial Senator Bail Organa, and by 5 BBY, he led a team of rebels against the Empire. Leevan Tenza was a member of this group, however an incident where he disobeyed orders and preemptively engaged an Imperial target led to his court-martial and defection to Saw Gerrera's Partisans.
In 2 BBY, members of Phoenix Cell, which also operated as part of the rebel network, managed to steal five antiquated Republic Navy BTL Y-wing light bombers from an Imperial salvage yard, which they planned to deliver to the unit. The Y-wings eventually made their way to Dodonna's unit, where they would become part of Gold Squadron, the cell's starfighter squadron led by Gold Leader Captain Jon "Dutch" Vander, protecting rebel convoys as well as attacking a few soft Imperial targets.
Shortly after the delivery of the Y-wings, Senator Mon Mothma was forced to flee her homeworld of Chandrila as a branded traitor after publicly denouncing the Empire. Gold Squadron took on the duty of protecting the Senator and escorting her to Dantooine, where they would rendezvous with other rebel cells. Mothma's Taylander shuttle, the Chandrila Mistress, rendezvoused with the Ghost for refueling of the shuttle's Y-wing escort, Gold Squadron.
The rebel ships were attacked by TIE fighters, an Arquitens-class cruiser and a Gozanti-class cruiser, and the Chandrila Mistress hyperdrive was damaged. Mothma and her crew were forced to evacuate onto the Ghost, and the rebels fled into hyperspace. At the advice of Phoenix Leader Hera Syndulla, the rebels took the old smuggler's route through the Archeon Nebula to escape the Lothal sector undetected. However, an experimental TIE/d "Defender" Multi-Role Starfighter starfighter decimated the squadron, until it was stopped by Vander and Ezra Bridger (flying as Gold Two).
The remaining squadron members, Vander and the original Gold Two, then arrived safely with the Senator at Dantooine. General Dodonna would arrive with Jun Sato and the rest of Phoenix Squadron shortly after, and, with the arrival of the other cells, the Alliance to Restore the Republic would be formed.
General Dodonna and the Massassi Group later arrived at Atollon to assist Commander Jun Sato and Phoenix Squadron in the long-planned attack to take out the Imperial Armory Complex on Lothal. However, the Massassi Group's trajectory, in addition to ISB Agent Alexsandr Kallus's Fulcrum transmission's trajectory, allowed Grand Admiral Thrawn and his Seventh Fleet to locate Chopper Base on Atollon.
When the Seventh Fleet arrived, the Massassi Group attempted to retreat, but were prevented from jumping into hyperspace by the Imperials' Interdictor vessels. Both the Massassi Group and Phoenix Squadron then fought Thrawn's forces, in an attack intended by Hera, Sato and Dodonna as a diversion to allow Lieutenant Commander Ezra Bridger to escape in the Gauntlet to inform Rebel Command and Senator Mon Mothma of Thrawn's siege. Ultimately, Sato sacrificed himself and his ship, the Phoenix Nest, by ramming Imperial Admiral Kassius Konstantine's Interdictor to allow Ezra to reach hyperspace.
The Massassi Group lost many of their cruisers and starfighters. The survivors then retreated to Chopper Base. There, they attempted to hold off Thrawn's ground forces. Dodonna, Captain Syndulla, and what remained of their forces then retreated following Ezra's return with forces from Clan Wren, who executed a strike to destroy the remaining Interdictor. Despite the Bendu's attacks, the Massassi Group and what remained of Phoenix Squadron were then able to escape the blockade. Together they went to Yavin 4.
In 1 BBY, the Spectres were assigned by Rebel Alliance leaders Mon Mothma, Bail Organa, and Jan Dodonna to spy on a newly-constructed communications relay on Jalindi at the suggestion of former ISB Agent Alexsandr Kallus. Their mission was to insert a spike in it, so the Rebels could spy on Imperial Fleet activities to make it easier for their forces to carry out operations. The Ghost crew was able to easily sneak into the upper atmosphere of Jalindi and install the spike, but the sudden arrival of Commander Brom Titus in his Arquitens-class command cruiser, the Marauder, forced the Spectres to scuttle their mission and destroy the relay instead. The sudden arrival of notorious extremist Saw Gerrera and his lieutenant Edrio in their UT-60D U-wing starfighter/support craft further complicated things, as Gerrera had already made plans to destroy the relay, tossing proton bombs onto the station's dish. He then invited Spectres Sabine Wren, Ezra, and Chopper onto his ship before the bombs went off. Gerrera's U-wing and the Ghost left Jalindi, but the sudden arrival of a Star Destroyer forced both ships to flee into hyperspace before Hera could pick up her people.
After the failed mission at Jalindi, Saw Gerrera requested Ezra and Sabine's help on a mission to Faos Station, in order to discover what the Empire was transporting in a supposed civilian ship, Freighter 2716. The rebels soon discovered that the freighter was transporting a large kyber crystal to the Tonnis sector, where it rendezvoused with a Star Destroyer. Gerrera sabotaged the crystal and escaped with Edrio, while Ezra and Sabine escaped with prisoners they found onboard in a Lambda-class T-4a shuttle. The kyber crystal soon exploded, destroying both the freighter and the Star Destroyer.
Some weeks after the events in the Tonnis sector, Mon Mothma received word from Lothal resistance group leader Ryder Azadi that the Empire had developed a new kind of TIE Defender, the TIE/D Defender Elite. Knowing of the danger, Mothma sent the Spectres back to Lothal to investigate. After smuggling themselves onto the planet, they rendezvoused with the Lothal Rebels. Hera and Kanan Jarrus, conducting a long-distance reconnaissance of Lothal City, discovered evidence that the Empire intended to put the highly advanced fighter into mass production. When Ryder took several members of the Spectres to spy on a test flight of the Defender Elite, Sabine had the idea to steal the prototype starfighter's flight data recorder, and she and Ezra snuck down to the airfield to do so. The arrival of Thrawn and Governor Arihnda Pryce complicated things, and led to the two Rebels stealing the entire prototype. After it crashed, Ezra and Sabine got the data recorder back to the Rebels' camp, and hid the Elite's hyperdrive to recover it later, to install on Ryder's U-wing.
Once the Spectres and Lothal Rebels had recovered the hyperdrive and installed it on the U-wing, Hera and Chopper flew the flight recorder back to Yavin 4 personally, making it through the heavy Imperial blockade. Once back at Alliance headquarters, the data was analyzed, and no weakness could be found. Hera told the leaders of the Rebellion, including Mothma, Organa, and Dodonna, that this meant the Rebels had to prevent the Defender Elites from being mass produced in the first place, and they had to destroy Lothal's factories. She added that there were people on Lothal who would be able to help, were an attack authorized. Mothma asked Hera and Chopper to step out of the room while the Alliance leaders debated. Eventually, Mothma came out to tell Hera that they had discovered the Empire was enacting Protocol 13, the evacuation of all its personnel, on Lothal. This gave Hera the impetus to barge back into the briefing, and she stressed that this news meant the Rebels did not have any more time to waste, as Lothal needed their help now. At this, the Alliance leaders agreed, and an attack was finally authorized. Hera was placed in command, and promoted to General. When she was able to get in contact with the rest of the Spectres, she informed them of the impending attack so they could prepare.
The attack force was comprised of 24 starfighters, a mix of X-wings and Y-wings. Hera's pilots included Cleat, Duke, Mart Mattin, and Secon Daree. They came out of hyperspace above Lothal, and the Imperial blockade launched TIEs in response. Hera ordered the X-wings to protect the slower Y-wing bombers. During the fighting, as the Rebels shot down many TIEs, Cleat and Duke were themselves shot down by Imperial ace Vult Skerris. In response, Hera lured him into a trap which disabled his personal Defender Elite's deflector shields and allowed her to shoot him down. He crashed into a light cruiser, which crashed into a Star Destroyer and sheared off its bridge superstructure, giving Hera's force an opening to Lothal's surface. However, Thrawn had been anticipating the attack, and had a second wave of TIEs waiting in the clouds of Lothal's atmosphere, which shot down all of the remaining Rebels.
On the surface, the other Spectres, who had destroyed several anti-air turbolaser turrets around Lothal City, watched in horror as the fighters plummeted. Only a few pilots survived to crash-land, including Hera, Mart, and Daree. Thrawn dispatched his personal assassin, Rukh, to capture any survivors, particularly Hera. Rukh captured Daree before tracking down Hera, Mart and Chopper, who were attempting to flee the city. Eventually, the three Rebels reached a sewer hatch, which was guarded by Imperial troops. In the process of luring away the guards and getting the hatch open, Rukh caught up to them, and fought Hera. She ordered Mart and Chopper into the sewers before she was captured. Pryce herself came to the scene, with some dismissive words before she stunned Hera. Mart and Chopper, upon making it to a sewer exit outside the city, were met by Kanan, who had turned back on his way to the Rebels' camp intending to rescue Hera.
In 1 BBY, Captain Cassian Andor traveled to the Ring of Kafrene to meet with one of his underground contacts, Tivik, a member of the Partisans, and learned about the Empire's possession of a superweapon, eventually known to be the Death Star. Andor was forced to kill Tivik when Imperial troops closed in, as he had suffered a broken arm that made him unable to escape the area. Andor then escaped back to Yavin 4 with the intel.
The Massassi Group sent the two scouts to Scarif system to investigate as they discovered the Death Star until the Mk I Superlaser is almost finished as they caught by the TIE fighters and the Imperial Star Destroyers, but it has failed.
Members of the Massassi Group then participated in the liberation of Jyn Erso from Imperial Detention Center & Labor Camp LEG-817 on Wobani. The extraction team was led by Ruescott Melshi, and included K-2SO.
Operation Fracture was undertaken by the Rebel Alliance and members of the Massassi group in order to extract Imperial scientist Galen Erso so he could testify before the Senate regarding the existence of a planet-destroying superweapon. However, before the mission began, the objectives were secretly changed to assassinate Erso instead.
This operation resulted in the Battle on Jedha, Destruction of Jedha City, the death of Saw Gerrera and many of his Partisans, the extraction of Bodhi Rook from Jedha, the destruction of the Eadu Energy Conversion Laboratory by Rebel forces, the death of Galen Erso, and the Rebels' awareness of the Death Star project.
After returning from Eadu, Jyn was called to a meeting of the Alliance leaders. Now possessing firm proof that the Empire had built a superweapon, the various leading Rebel politicians could not decide what to do about it, as most of them were terrified of the Death Star's destructive potential. Eventually, no decision was made, despite an impassioned plea from Jyn. This led Jyn, along with Cassian, Baze, Chirrut, Bodhi, K-2SO, and several volunteers, to go to Scarif against orders. The Citadel Tower on Scarif housed the Imperial archives, including a complete copy of the plans of the Death Star. The team, which dubbed themselves "Rogue One" on the fly, intended to infiltrate the facility and steal the plans.
They passed through Scarif's Shield Gate in a stolen Imperial cargo ship, which had not yet been registered as stolen to the Empire. Upon landing, Jyn, Cassian and K-2SO infiltrated the tower itself, while the Rebel commandos who had come along staged a loud, noisy diversion. While this was going on, Rebel Command back on Yavin 4 eventually received word that there was fighting on Scarif, and immediately sent reinforcements. The fleet was led by Admiral Raddus from his flagship, the Profundity. Docked to the capital ship was the corvette Tantive IV, Princess Leia Organa's ship, which had been undergoing repairs. As Jyn and Cassian snuck inside the vault and stole the data-tape with the Death Star plans, the other members of the group were fighting and dying against the Imperials, who thought there were far more Rebels on the planet than there actually were.
The arrival of the Rebel reinforcements, mostly compromised of the Massassi Group, caught the two Star Destroyers on guard at the Shield Gate by surprise, and many Rebel fighters were able to get through the gate before it was closed. At the Citadel, an angered Krennic managed to have a transmission sent for reinforcements from offworld. Jyn eventually made it up to the transmitter at the top of the tower by herself, as Cassian had been injured in the vault and she thought he was dead. During the space battle, the damaged Sphyrna-class Hammerhead corvette Lightmaker rammed one of the two Star Destroyers, disabled by ion weaponry, into the other, sending all three ships crashing into the Shield Gate, destroying it. At the Citadel Tower, Jyn managed to transmit the Death Star plans to the Profundity, despite some interference from Krennic, who was shot and injured by Cassian when he arrived. The Death Star, alerted to the fighting, arrived soon after. Grand Moff Wilhuff Tarkin, in command, decided to do to the Citadel Tower what he had done to Jedha, and had the station's superlaser fired on a low setting, destroying the facility and killing Krennic, Jyn, and Cassian. The Star Destroyer Devastator arrived as the remaining Rebels were fleeing. Onboard the Rebel flagship, the technical readout of the battle station was downloaded onto a disc and rushed to the Tantive IV, where it was handed off just as Darth Vader, who had personally boarded the stricken Profundity, reached the door. The corvette escaped, leaving the Sith Lord decidedly displeased.
After the Death Star destroyed Alderaan, Princess Leia, who had been forced to watch, was rescued from the battle station, with the stolen plans concealed in her astromech droid, R2-D2. The ship Leia and her rescuers, Luke Skywalker, Han Solo, and Chewbacca, were travelling on, the Millennium Falcon, had had a tracking device planted on it by the Empire. Leia used this to lure the Death Star to the Yavin system, with the aim of destroying it. Once the plans were finally analyzed by Rebel Command, they discovered the weakness that had been deliberately built into the Death Star: a thermal exhaust port leading directly to the station's reactor.
Due to the Massassi Group's significant losses at Scarif, the Rebels could only field three squadrons of starfighters: Red Squadron and Green Squadron, composed of X-wings; and Gold Squadron, composed of Y-wings. Red Squadron had also flown at Scarif. Luke Skywalker was assigned to the slot of Red Five. Han, who was both a cynic and owed large debts to the crime lord Jabba Desilijic Tiure, had no intention of staying, and made ready to leave the system. Red Squadron was commanded by Garven Dreis, and its roster included Wedge Antilles and Biggs Darklighter. Gold Squadron was commanded by Jon Vander, and included Davish Krail and Evaan Verlaine. The intended plan of battle was that the X-wings would hold off the TIE fighters while the Y-wings flew into the trench where the exhaust port was located and launch their proton torpedoes into it. Due to the Rebels' limited resources, each starfighter carried only two torpedoes.
During the fighting, Vander and his two wingmen, Krail and Dex Tiree, slipped off to do the trench run, hoping to have gone unnoticed. However, Darth Vader, onboard the Death Star, noticed, and flew out in his custom TIE Advanced. He shot down all three Y-wings, but Krail was able to report to Dreis that the shots had come from behind before he died. The losses inflicted on the Rebels, as Yavin 4 came closer and closer into the sights of the battle station, prompted Dreis to attempt a trench run himself. Vader shot down his wingmen, but Dreis was able to fire his torpedoes at the exhaust port. However, he missed, and ordered Luke to do a trench run before he was shot down by Vader. At this point, there were few Rebel fighters left, with Evaan Verlaine being the only remaining Y-wing. Luke and his wingmen, Wedge and Biggs, entered the trench. They were soon pursued by Vader and his wingmen, who shot down Biggs and damaged R2, serving as Luke's astromech, and Wedge's fighter. Luke told Wedge to leave, as with his damaged fighter there was nothing he could do. Vader had just centered Luke in his sights when he was surprised by the sudden entry of the Millennium Falcon, which shot down one of his wingmen and caused the other one to knock the Sith Lord's fighter off into space. Han had had a pang of conscience and changed his mind, coming back to assist in the battle. With no Imperial fighters pursuing, Luke used the Force to perfectly fire his proton torpedoes into the exhaust port. The three remaining Rebel fighters and the Falcon fled back to Yavin 4 as the Death Star exploded.
Immediately following the medal ceremony for Han Solo, Luke Skywalker, and Chewbacca for their bravery in successfully destroying the Death Star and saving the Rebel Alliance from total destruction, General Dodonna demanded that the evacuation of Yavin 4 start right away since the Imperials still knew of their location, regardless of the costly Rebel victory.
- LEGO Star Wars: Droid Tales — "Mission to Mos Eisley"