Byss/Legends

Byss was a planet in the Deep Core, near the center of the galaxy, discovered no earlier than 45 BBY. A local day lasted 31 standard hours, and a local year lasted 207 standard days. It was the endpoint of the Byss Run.

Byss itself was somewhat of a myth, seeming to be the perfect place to live. Its eerie blue-green glow, caused by its sun, also added to the strangeness of the world. Despite this outward appearance, however, Emperor Palpatine's dark side energies were everywhere, corrupting not only the inhabitants, but the planet itself.

Byss was the secret throne world of Palpatine and the location of his towering Imperial Citadel. He also kept his secret supply of clone bodies there.

History
Around 30,000 BBY during the Pre-Republic era, Byss was ruled by the space-faring Rakata. Using Force-based hyperdrives, they traveled to many worlds around the galaxy that possessed significant signatures in the Force, uniting them to form the Rakatan Infinite Empire. They constructed large temples on Byss. After five thousand years of galactic dominance, the Rakata retreated to their homeworld. Their temples collapsed into ruins overtaken by the jungle, leaving no clues for later settlers as to how or why they died out.

The surface of the world was dotted with "spectacular" ruins that were said to be pre-Expansion Era. During the Galactic Empire's expansion into the Deep Core region, Palpatine selected Byss as his personal retreat and his secret throne world. Thousands of non-Human slaves were forced to labor in the "recolonization efforts" on Byss including the Utapauns and Gamorreans after the Clone Wars.

It was on Byss that a number of captured AgriCorps workers and Padawans were held captive under the supervision of Sly Moore, until the Emperor introduced them to Darth Vader. Vader killed all but four of them; these four he trained to be Inquisitors. One of the chosen, named Antinnis Tremayne, would eventually become a High Inquisitor. It was the site of the Sarlacc Project, where a Super Star Destroyer prototype was under creation before being destroyed by a group of freedom fighters and pirates under Bail Prestor Organa and Alya Aldrete. The Emperor drew ignorant followers to the planet under the pretext that it was a paradise world. Among them were survivors of the Destruction of Alderaan, which he offered to resettle on Byss in a public speech delivered following the destruction of the world. Once they had settled into their new lives on the paradise world, the Emperor revealed his true plans for Byss. Immigrants lived out their lives in elaborate pageants and amusements, which distracted them from what Palpatine was really doing: draining their life energies to power his abominable experiments. Eventually, Byss was entirely enveloped in the dark side of the Force. This was evident by the eerie blue-green sunlight that bathed the world in a strange glow.

Byss had orbital drydocks for both World Devastators, Super Star Destroyers and later on, the Galaxy Gun. At the height of its power, the world was encircled by warships and battle stations for the Emperor's protection.

Byss was fanatically loyal to the Emperor even after his first death at the Battle of Endor. When the Emperor was reborn in a new clone body, Byss became the capital world of the Galactic Empire, which Palpatine planned on rebuilding into the beginnings of a universe spanning magocracy. Byss was destroyed during a battle with the New Republic when Eclipse II rammed the Galaxy Gun, causing the last projectile of the Galaxy Gun to destroy the planet.

In 14 ABY, Tavion Axmis absorbed the lingering dark side energy from the remains of Byss during her campaign to resurrect Marka Ragnos. Rosh Penin was sent to investigate, but was seduced to the dark side by Tavion. Kyle Katarn and Jaden Korr later embarked on a mission to Byss to discover Penin's fate. The Raven's Claw was captured by a Dreadnaught-class cruiser among the planet's remains, though the Jedi ultimately escaped the clutches of the Imperial Remnant.

Behind the scenes
According to the Dark Empire Sourcebook, Byss orbited a binary system of a blue star and blue dwarf, but according to Byss and the Deep Core, Byss is in a single-sun system.

The board games Risk: Star Wars Clone Wars Edition and Risk: Star Wars Original Trilogy Edition mistakenly place Byss in the Core Worlds region.

The Official Star Wars Fact File 93 erroneously lists the Abyssin as a native species of Byss, mistaking the world for the Outer Rim planet of the same name.