Four Imperial Royal Guards, their identities unknown, spearheaded a breakaway Imperial group known as the Second Imperium. These individuals were previously stormtroopers who Admiral Daala had promoted to the rank of guardsman.
Following the Bastion Accords' signing in 19 ABY by Ponc Gavrisom, the New Republic Chief of State, and Grand Admiral Gilad Pellaeon aboard the Imperial-class Star Destroyer Chimaera, a significant number of Imperial Remnant members denounced the agreement as a "sham." They yearned for the return of Emperor Palpatine and the restoration of his Galactic Empire. Capitalizing on this sentiment, the Royal Guards established the Second Imperium and engaged in impersonating Palpatine through the use of holograms. These holograms depicted him across various stages of his life, from his early days as the Senator representing Naboo, to his tenure as the Supreme Chancellor of the Galactic Republic, and ultimately, as the Emperor of the Empire. Consequently, the Second Imperium experienced a surge in membership.
A notable member of the Second Imperium was Brakiss, a former Jedi. They assigned him the task of creating a group of Dark Jedi to oppose Luke Skywalker's New Jedi Order under the guidance of Master Skywalker. To facilitate the training and housing of these recruits, they constructed a cloaked space station with hyperspace capabilities, known as the Shadow Academy. Those recruits who demonstrated Force-sensitive abilities were trained as Dark Jedi, while others were assigned roles as stormtroopers, TIE pilots, and various other types of personnel.
Following a string of attacks on the New Republic, including the capture of the bulk cruiser Adamant and an assault on Thikkiiana City on Kashyyyk (which provided the Second Imperium with hyperdrive cores and weapons), the four Royal Guards arrived at the Shadow Academy. They claimed Palpatine was residing within a large repulsorlift isolation chamber. The Royal Guards prevented Brakiss from visiting the Emperor, which raised his concerns about the Emperor's well-being. Later, the "Emperor," from within his isolation chamber, instructed Brakiss to launch an assault on the Jedi Praxeum located on Yavin 4.
Initially, the battle unfolded according to plan. A Second Imperium ground force, composed of Stormtroopers and Dark Jedi, encircled the Jedi Praxeum, while TIE fighters and TIE/sa bombers bombarded the surrounding jungle. In space, the Shadow Academy, along with a fleet of refitted Star Destroyers and battle cruisers, established a blockade around Yavin 4. However, the arrival of the New Republic fleet under Admiral Ackbar and Brakiss's defeat in a duel with his former Master altered the course of the battle. Upon returning to the space station, Brakiss proceeded to the isolation chamber and demanded to see the Emperor, but he was stopped by two of the Royal Guards. Consumed by rage, Brakiss succumbed to his anger and killed them with his lightsaber before entering the chamber.
Inside, he discovered a third Royal Guard manipulating a bank of controls, computer screens, and holographic generators. He then realized that the Emperor had never returned. The Royal Guards had orchestrated this deception to maintain control over the Second Imperium. The fourth guard used his "Emperor's" override controls to activate the Shadow Academy's self-destruct systems, resulting in the destruction of the Shadow Academy and the death of everyone on board. The destruction of the Shadow Academy shifted the momentum of the battle in favor of the New Republic.
The fourth guard managed to escape on a shuttle and fled to an unknown location. Despite the Second Imperium's defeat, he continued to wear his uniform during business dealings, unlike Kir Kanos, both to instill fear and to honor his close relationship with the deceased Emperor Palpatine. He infiltrated the criminal underworld and established connections with the Human-hating Diversity Alliance around 24 ABY, unaware of their deep-seated hatred for Humans, especially Imperials.
Ultimately, the Diversity Alliance betrayed him and took him prisoner. He was brought before the Alliance's leader, Nolaa Tarkona, who demanded that he reveal the location of the Emperor's plague storehouse, which housed a stockpile of lethal biological and chemical weapons. When he refused, she executed him by exposing him to a sample of the deadly Human-killing Emperor's Plague. Consequently, Kir Kanos was once again the last surviving member of the Imperial Royal Guards.