The Trayus Academy was an ancient Sith academy located on the planet Malachor V. The Jedi Knight Revan discovered the abandoned structure during the Mandalorian Wars. During the Jedi Civil War, he used it to convert Jedi to the Dark Side and train them as Sith assassins. After the Sith forces were defeated in that conflict, the Academy became the headquarters of the Sith Triumvirate and continued to serve as the training ground for Sith assassins until Malachor V was destroyed in 3951 BBY.
The Trayus Academy was a training center built millennia before the Mandalorian Wars by a Sith Empire. Eventually, the Academy as well as the planet was abandoned by the Sith.
During the Mandalorian Wars in the year 3961 BBY, a Jedi Knight named Revan rediscovered Malachor while scouting for bases along the Outer Rim when he heard stories of a world the Mandalorians were forbidden to step foot on according to their culture. Wishing to discover why Malachor V was a taboo world to the Mandalorians, Revan secretly investigated the planet, unaware he was about to discover far more than what he was looking for.
Revan came across the Trayus Academy and within he rediscovered the location of the planet Korriban and uncovered evidence that the Sith Empire continued to exist beyond the boundaries of known space and continued to pose a threat to the galaxy. Unbeknownst to even his closest confidants such as Malak at the time, Revan constructed a stronghold and used Malachor's dark side energies to bind the most trusted of his followers to his will. The Sith assassin order was founded as a result.
The shattered remnants of Malachor V.
Returning to the war, Revan led the Republic to victory over the Mandalorians. One year after rediscovering the Trayus Academy, Revan forced a final confrontation with the Mandalorians above Malachor V. In utter secrecy, he had prepared a superweapon, known as the "Mass Shadow Generator," which was to be the centerpiece of a trap with which he hoped to bring about a conclusive end to the Mandalorian Wars. Overseeing the device's use was a trusted Jedi General, Meetra Surik (the future Jedi Exile).
Revan lured the Mandalorians to Malachor, and as the fighting grew intense, on his order, Surik, one of his most trusted generals activated the generators. In the resulting cataclysm, a significant portion of both the Mandalorian and Republic fleets were drawn from orbit into a vast gravity vortex that was powerful enough to crush the countless ships into the planet's crust and fracture the world to its core. Remarkably, the Trayus Academy survived the catastrophic event intact.
Following his victory, Revan traveled with Malak to the Unknown Regions in search of the Sith Empire. There on Dromund Kaas he encountered the Sith Emperor and were subdued to the Emperor's will, becoming Darth Revan and Darth Malak. The Emperor then ordered them to search for the Star Forge, planning on using it to speed up the building of the Sith armada. During the search, they broke free from the Sith Emperor and founded their own Sith Empire. During the Jedi Civil War, circa 3959–3956 BBY, Darth Revan used the Trayus Academy as one of several secret Sith bases dedicated to the conversion of captured Jedi. Throughout the war, Jedi were captured by his Sith assassins, and other specially trained forces, and brought to the Academy. The corruptive nature of the location weakened their wills so that Revan and his loyal servants could easily lure them to the dark side. In such places, he converted hosts of Jedi into loyal Dark Jedi and Sith assassins for his empire.
A year after the Sith were defeated by the Galactic Republic during the Jedi Civil War, a redeemed Revan departed for the Unknown Regions in a solitary quest to defeat the Sith Empire. Meanwhile, Revan's former Jedi Master, a Jedi named Kreia, feared that her teachings had led Revan to the dark side and went in search of her pupil—a search that would eventually lead her to Malachor V. Kreia walked upon the surface of the planet and was overcome. She fell to the dark side and became Darth Traya. She studied the planet's secrets and rose to command the Trayus Academy and the Sith Assassins which still lingered there. The Academy was reestablished by Traya to train, convert, and create a new generation of Sith who were used to destroy the Jedi Order.
Trayus Core, the innermost sanctum of the Trayus Academy.
Darth Traya soon discovered two Sith Lords in which she saw the potential of the death of the Force. Darth Nihilus and Darth Sion joined her cause and together they formed a Sith Triumvirate. Under the leadership of the three Sith Lords, the Trayus Academy reached its zenith. Based within their hidden Academy on Malachor V, the Sith Lords commanded legions of Assassins who hunted the remaining Jedi to the very brink of extinction. Darth Traya had managed to unite the fragmented Sith forces through their mutual hatred and led them to victory once more, but her success would not save her. In a sudden act of betrayal, her two apprentices joined forces, stripped her of power, and exiled her.
In 3951 BBY, Kreia located Meetra Surik who was the only Jedi who had fought with Revan against the Mandalorians at Malachor V and yet remained uncorrupted. Wishing to rid the galaxy of her fallen apprentices and ultimately the death of the Force, Kreia orchestrated events to set up a final confrontation between herself and Surik at the Trayus Academy. After slaying Darth Nihilus, Surik arrived at the Academy to combat the Sith lurking there. She invaded the academy and eliminated every Sith minion that crossed her path. Moments after defeating Darth Sion and killing Kreia in a series of lightsaber duels, Malachor V was torn apart when the Mass Shadow Generator was reactivated on Surik's orders.
The entrance of the Trayus Academy from the Malachor Depths opened onto an antechamber that connected to the eastern and western halls of the complex. The Trayus Crescent, located to the west, was a hall with many alcoves that were frequented by Sith commandos. To the east, the Trayus Proving Grounds was a warren of small and cramped rooms in which many Dark Jedi and Sith commandos could be found. The northern point of both wings led to the Academy's central area, the last bit of open space before the innermost sanctum of the Trayus Academy was known as the Trayus Core.
In the video game Star Wars: Knights of the Old Republic II: The Sith Lords, if the player takes the dark side path, under this non-canonical timeline both Malachor V and the Academy would remain intact.
It's unknown whether the Sith Empire founded by Adas or the Sith Empire ruled by the Exiles and their descendants built the Trayus Academy or when it was abandoned.
- Star Wars: Knights of the Old Republic II: The Sith Lords: Prima Official Game Guide
- Jedi vs. Sith: The Essential Guide to the Force
- Knights of the Old Republic Campaign Guide
- Jedi Academy Training Manual