The Trioculus incident involved a struggle between the Alliance to Restore the Republic and a breakaway group from the Galactic Empire, under the command of Trioculus. This occurred in the year 5 ABY. Unknown to all participants, Darth Sidious secretly orchestrated the entire conflict. His aims were to prevent the Republic from discovering his clandestine rebirth in the Deep Core of the galaxy, and to recover Darth Vader's right hand glove to accelerate his own resurrection. By fueling Trioculus's ambition, Sidious also manipulated him into searching for the Lost City of the Jedi and ancient Sith amulets.
According to the Prophets of the Dark Side's legends, the Force would create a powerful, charismatic individual with three eyes once per millennium. Sly Moore, an advisor to Galactic Republic Supreme Chancellor Palpatine, oversaw experiments that involved exploring the essence of life in a Bordali woman named Niobi. These radical experiments resulted in harmful mutations that scientists eventually eliminated, except for a third eye in Niobi's son, Trioculus. This additional eye possessed hypnotic abilities. Moore also supervised Mammon Hoole and Borborygmus Gog's experiments to spontaneously create life, but she disappeared after becoming interested in using the Force to influence midi-chlorians to fertilize a zygote.
After disappearing from public life, Moore was rumored to have died giving birth to a nameless mutant, who was secretly taken away by Emperor's Hand Sarcev Quest. Niobi and Trioculus were exiled to work in the spice mines of Kessel. There, Trioculus escaped constant bullying by studying literature and warfare, aided by Lord Overseer Reskell Twane. The young mutant became a devoted follower of the Galactic Empire, the fascist state that Palpatine had created from the Republic based on the Sith Grand Plan. After Trioculus exposed a Rebel cell in his village, he gained the attention and friendship of sector Grand Moff Bertroff Hissa and was promoted to Supreme Slavelord after Twane's transfer. Trioculus never forgot Moore while on Kessel, particularly her unofficial title of "Queen of the Empire."

Palpatine also had a biological son, another three-eyed mutant named Triclops, who was banished at birth. Triclops grew up in Imperial asylums, suffering emotional and physical trauma from shock therapy and dark side energies. He fell in love with a Jedi nurse, [Kendalina], who bore him a son named Ken. A Jedi Master took Ken to the underground Lost City of the Jedi on Yavin 4. Triclops was later sent to the Kessel spice mines, where Trioculus dominated him.
In 4 ABY, Alliance hero Leia Organa killed Jabba the Hutt on Tatooine. Later on Kessel, a slave riot led to Twane's capture by corrupt administrator Moruth Doole, who offered him to Trioculus in exchange for control of the Supreme Slavelord's territory. Trioculus sought Hissa's advice and was told that a loyal Imperial did not give in to threats. Trioculus followed this advice, showing no remorse when his surrogate father was fed spice grubs and frozen in carbonite, impressing Hissa with his resolve.

Darth Vader, Palpatine's Sith apprentice, wore a right-handed glove containing a powerful Sith amulet that once belonged to Skere Kaan. During the Battle of Endor in 4 ABY, Vader's right hand was cut off in a lightsaber duel on the Death Star II by his son, Luke Skywalker. Vader returned to the light side of the Force and killed Emperor Palpatine by throwing him into the battle station's reactor shaft. Exposed to Palpatine's force lightning, Vader died in his son's arms as the Death Star II exploded due to an Alliance attack. His detached glove survived the explosion, was sucked into a black hole, and landed on the aquatic world of Dac. The Galactic Civil War shifted in favor of the Rebel Alliance, who became the New Republic, though many still considered them the Alliance.
After Palpatine's death, Imperial warlords fought for power. To control the galactic population's desire for free speech, acting Imperial-sovereign Sate Pestage tasked Cronal, a former prophet of the Dark Side and HoloNet propaganda producer, with establishing the Church of the Dark Side as the new state religion. Since the real prophets, including [Supreme Prophet](/article/supreme_prophet] Kadann, had fled to Bosthirda after disagreeing with Palpatine, Cronal filled the church with Imperial spies and actors, including the Bimm thespian Rajah Ubooki disguised as Kadann. The false prophets broadcasted from Space Station Scardia, with "Kadann" delivering cryptic prophecies. These prophecies captured the imagination of the Imperial populace, who would only accept someone with the church's dark blessing as their new emperor.
Pestage told Ubooki about Vader's glove, rumored to have survived and disappeared through the Endor Gate wormhole. Imperial factions spent considerable resources searching for the glove, which the Senate Planetary Intelligence Network (SPIN), a New Republic spy network established by Chief of State Mon Mothma, noticed. SPIN operatives doubted the glove's supernatural powers but were tasked with finding it. Ubooki prophesied that a new Emperor would wear the glove of Darth Vader, which he desired as a trinket. Pestage's real goal was to aid Palpatine's recovery, as his spirit had returned from chaos and entered a clone body on Byss. Pestage believed the amulet in the glove could amplify Palpatine's dark powers and hasten his return to galactic dominance.
Rumors about Palpatine's son, rumored to be three-eyed or the son of one of his concubines, had persisted for years. In 5 ABY, one year after Endor, the Central Committee of Grand Moffs, led by Hissa, decided to act against Imperial Intelligence Director Ysanne Isard by declaring their own Emperor candidate. Hissa, impressed by Trioculus's mettle, asked the mutant to capitalize on the rumors about Palpatine's son. After Vader's glove became public knowledge, the Moffs prepared a coronation ceremony in Kessendra, a city on Kessel, to reveal Trioculus as their new emperor, claiming he was Palpatine's son. SPIN learned of the coronation and Kadann's prophecy and sent Skywalker's droids C-3PO and R2-D2, disguised as mining droids, to spy on the event.
After a briefing on Yavin 4, Han Solo and Lando Calrissian transported the droids to Kessel on the Millennium Falcon.