Ilum

"There is no place more sacred to the Jedi."

- Jedi Padawan Ahsoka Tano, regarding Ilum's Crystal Caves

Ilum was a snow-covered planet located in the 7G sector of the Unknown Regions, within the Ilum system. In the system, Ilum was fifth from its parent star Asar, a blue dwarf, located roughly equidistant from Asar and the system's cometary cloud. Ilum had been utilized by the Jedi Order for the Gathering, a rite of passage in which Jedi younglings must find and harvest kyber crystals for their lightsabers, for thousands of standard years.

Description
The planet Ilum was situated in the Ilum system, a star system located in a part of the Unknown Regions known as the 7G sector. Ilum was an arctic world; that is, the entire planet was covered in ice and snow, and was therefore inhospitable to most species. Hidden beneath Ilum's frigid surface was what came to be known as the Crystal Cave. Within the maze-like crystal caves grew kyber crystals, which brought the Jedi Order to Ilum so they could harvest the crystals in a rite of passage known as the Gathering, in which Jedi initiates harvested their crystals by attuning themselves to the Force. As such, Ilum was a holy site for the Jedi Order for centuries.

By 18 BBY, the Empire had already corrupted Ilum, draining its resources dry as well as having destroyed entire parts of the planet's surface, as they were harvesting kyber crystals for the Death Star; the destruction was visible even from space. When Jedi Purge survivor Ahsoka Tano returned to the planet, she noted that there were at least two Star Destroyers and a mining ship in orbit around the planet. Chunks of the planet had been carved away, exposing the rock and lava that boiled up from the planet's core.

Discovery
Ilum's recorded history began tens of thousands of years before the Galactic Empire's creation. A Jedi scout performed Force-assisted hyperspace navigation through hyperspace routes, taking her to the Unknown Regions. She was drawn to a powerful resonance in the Force, which brought her to Ilum. The scout reported that Ilum was devoid of any sentient life, but was rich with non-sentient animals.

Jedi uses
Survey teams were sent out later, and ultimately discovered the vast quantity of naturally-forming kyber crystals such as pontite and mephite. The Jedi Order's High Council dispatched scholars, artisans and warriors to secure the planet. The Council decided that the planet should be kept secret to the galaxy at large. Hyperspace surveyors mapped out an uninterrupted hyperspace route from the Core World of Metellos directly to Ilum, and was incredibly complex. Eventually, all mentions of Ilum were deleted and it was kept from local, sector-wide and galactic star maps.

The Jedi Temple on Ilum remained the last sign of intelligent life on Ilum, but was almost entirely covered by ice. All other bases on Ilum were removed by the Jedi. Ilum became a bigger supplier of kyber crystals when other planets exhausted their supplies.

Clone Wars
As was tradition, a group of Jedi younglings would travel to Ilum to build their first lightsabers, aboard the Crucible and escorted by a higher-ranked Jedi. In 20 BBY, one such Gathering took place in the midst of the Clone Wars. Padawan Ahsoka Tano escorted the younglings Byph, Ganodi, Gungi, Katooni, Petro, and Zatt to the Crystal Cave, where Grand Master Yoda awaited their arrival. Each youngling endured different trials to retrieve their crystals.

All of the younglings left Ilum aboard the Crucible, where they would be instructed by the architect droid Huyang on the construction of their lightsabers.

Under the Empire
A year after the Gathering took place, the Galactic Empire was proclaimed. The Empire quickly began strip-mining Ilum, revealing magma bubbling from Ilum's core. The entrance to the Jedi Temple had been destroyed to allow access to the crystal caves. A massive mining ship, as well as two Imperial Star Destroyers, stood watch over the planet to gain its riches.

Inhabitants
Ilum was not home to a large amount of people, with just 5,200 sentient inhabitants. Of those 5,200, 45% were support crew, 30% were temporary researchers, 20% were military, and the remaining 5% were other individuals living on-world.

Locations
Ilum's main attraction was its Jedi temple, hidden beneath a large cliff of ice. Beneath that temple was the planet's massive complex of crystal caves where a vast quantity of kyber crystals could be found, and the site of the Gathering. The remainder of Ilum's surface was barren, save for canyons and mountains.

Behind the scenes
Ilum first appeared in Star Wars canon in the sixth episode of the fifth season of the animated television show Star Wars: The Clone Wars, which was titled "The Gathering" and aired on November 12, 2012. The planet originated in Star Wars Legends, where it first appeared in the junior novel Jedi Quest: Path to Truth, which was released on September 1, 2001.

Appearances

 * Catalyst: A Rogue One Novel
 * Ahsoka
 * Star Wars Jedi: Fallen Order
 * Rebel Rising
 * Star Wars Jedi: Fallen Order
 * Rebel Rising