The Horizon Guard was an elite unit of Force-sensitive warriors created by Eternal Empress Vaylin after assuming the throne, the ranks of the Horizon Guard were handpicked by the Empress from the Knights of Zakuul ranks. The Guard served as the Empress's personal guard.
An elite unit of Force-sensitive warriors within the Eternal Empire, the Horizon Guard, was created by Empress Vaylin after assuming the throne. The unit consisted of former Knights of Zakuul, handpicked by the Empress. The main task of the Horizon Guard was to serve as the Empress's personal guard, as well command situations in the field.
In 3630 BBY, after Eternal Emperor Arcann was defeated by the Commander of the Alliance, his sister High Justice Vaylin assumed the control of the throne and of the Eternal Empire. One of Vaylin's first acts as an Empress was the purge of the entire cadre of Zakuul Knights that were in charge of protecting the Emperor, after the purge Vaylin created the Horizon Guard an elite unit handpicked from the remaining Knights of Zakuul. The unofficial motto "I serve for life, but I don't serve for long" was created by the Horizon Guards ranks, since they were likely to fall victims to Vaylin's erratic temper.
In 3630 BBY, during the Eternal Empire invasion of Voss, Empress Vaylin commanding from the Spire on Zakuul, ordered several Horizon Guards to lead the invasion and to report the progress of the battle to her. During the invasion several Horizon Guards and skytroopers assaulted the Tower of Prophecy where an improvised command center for the Alliance's forces was located, but they were defeated by the Alliance Commander and its companions. Some time after the Invasion of Voss, Horizon Guards accompanied Empress Vaylin and SCORPIO on a mission to infiltrate and capture the Gravestone, after successfully capturing the ship and its crew, the ship's captain Koth Vortena contacted the Alliance asking for assistance. The Alliance's forces arrived to rescue the vessel and the Commander infiltrated the vessel to meet with Koth Vortena, during their effort to retake control of the ship two Horizon Guards, Tragus Rova and Vella Zarkot, intercepted them in order to capture them and deliver them to Vaylin, but both of them were defeated by the Outlander.
During the Grand Festival of Empress Vaylin, Horizon Guards were tasked with guarding strategic points throughout the Palace of the Eternal Dragon. When Arcann and his loyalists as well the Commander, Theron Shan and Zakuulan insurgents ambushed the party in an attempt to stop Vaylin, Horizon Guards fought against the invaders while the Empress tried to escaped from palace. After Vaylin reached her personal flagship and fled to Nathema where she hoped to remove her mental conditioning that didn't allowed her to use all her potential with the Force, once on Nathema, she took several Guards with her to the surface and ordered them to remain and protect the entrance to the Sanitarium. Shortly after Vaylin's arrival, the Guards were killed by the Alliance Commander and Lana Beniko who were trying to stop Vaylin from breaking her mental conditioning.
Once Vaylin successfully broke free from her mental conditioning she launched an attack on Odessen, several Horizon Guards such as Imperator Sunfell participated on the assault providing help on the front lines and other contingent escorted Vaylin and her prisoner to the Alliance base were she would confront the Commander, but ultimately would lead to the Guards and Vaylin's deaths.
After the fall of the Eternal Empire, the remaining Guards scattered across the galaxy. Former Horizon Guard Scout Captain Sterla joined Battalion Commander Tassar in an effort to build a new Star Fortress on Rakata Prime, but ultimately their plans were stopped by the Eternal Alliance's forces. In 3629 BBY, another former Horizon Guard Vinn Atrius, started a campaign that was determined to destroy the Alliance by using Zildrog, an ancient superweapon from Iokath. Atrius established a base of operations on an abandoned listening post and began seeking allies to join his secret Order of Zildrog. Atrius' plans were eventually stopped, in 3628 BBY, after Theron Shan infiltrated the order and allowed the Commander to locate him on Nathema and capture him.
In 3626 BBY, the Alliance Commander alongside Kira Carsen, and Scourge boarded a ship which transported Satele Shan and her students, who had been rendered unconscious by Tenebrae's curse. The three of them entered Satele Shan's mind where Tenebrae was located. Before Tenebrae's death several spirits of all the people he had manipulated over the centuries appeared before him, several Horizon Guards could been seen among the multitude that joined the Commander to defeat the Sith Emperor once and for all.
The Horizon Guards used lightsaber pikes and lightsabers as their preferred weapon. Horizon Guards usually wore a black and gray armor, but a white variation was also known.
The Horizon Guard first appeared in the 2016 digital expansion Knights of the Eternal Throne for BioWare's MMORPG Star Wars: The Old Republic. The Horizon Guard armor can be bought by players from the in-game store, which they can customize and wear.