Lola Sayu, situated within the Belderone sector of the Outer Rim Territories' Lola Sayu system, was once a planet characterized by sulfurous conditions and volcanic activity. This celestial body, which glowed a striking purple when viewed from its orbit, had undergone a mysterious cataclysm that exposed its molten core. Over the course of several millennia, it slowly disintegrated until it was discovered by the Galactic Republic. The galactic government, in collaboration with the Jedi Order, established a high-security prison known as the Citadel in 522 BBY to house wayward Jedi. Although under Republic control for centuries, Lola Sayu's allegiance shifted when the Confederacy of Independent Systems captured it during the Clone Wars.
The Separatists, having seized the Citadel, appointed Phindian Commander Osi Sobeck as its overseer. They also blockaded Lola Sayu with a fleet stationed in orbit, transforming the Citadel into a nearly impenetrable fortress. Later in the conflict, Jedi General Even Piell of the Republic was incarcerated within the Citadel following his capture by the Separatists, both sides vying for control of the strategically important Nexus Route. Subsequently, the Republic dispatched a team of Jedi and clone troopers to free Piell and his comrades, aiming to secure the coordinates crucial to their war effort. This mission evolved into a desperate attempt to escape the crumbling planet, ultimately succeeding in their departure from Lola Sayu.
Following the war's conclusion, rumors circulated about the Citadel being cursed and haunted. Nevertheless, a remnant garrison of Separatist battle droids, led by a malfunctioning droid operating under a modified directive, remained active within the facility, targeting all Force-sensitives. This directive led to the imprisonment of a Force-sensitive youngling within the Citadel, culminating in a decisive battle with a Jedi warrior to liberate the child. By 9 ABY, time had passed and Lola Sayu was under the authority of the New Republic, housing prisoners such as Unga Toba, who was serving a twenty-five year sentence for illegal computer access.
Lola Sayu, a decaying terrestrial planet with volcanic traits, was located in the northeastern portion of the galaxy. It was a member of the Lola Sayu system, situated within the Belderone sector of the Outer Rim Territories. Positioned in grid square R-6 on the Standard Galactic Grid, the planet was situated slightly west of the Perlemian Trade Route super-hyperroute, connecting the sulfurous world to Aralia and Lianna. Furthermore, Lola Sayu was located near the Salin Corridor, where it intersected with Quell and Sy Myrth. Due to a past cataclysmic event that fractured Lola Sayu, its gravitational field contained planetary debris, making spatial approaches perilous.
From outer space, Lola Sayu displayed a purple glow originating from its northern volcanic crust. The planet's surface featured caves, crevasses, hills, and mountains, along with cracks leading to the destroyed southern hemisphere, illuminated by the lava from its exposed core. The surface was treacherous, with roads bordering lava flows from the Sulfur Sea, leading to cave systems or steep valleys. Water was scarce, and no plant or animal life was known. Despite its fragility, Lola Sayu was habitable, with a breathable, oxygen-mixed atmosphere suitable for species like humans, Phindian, and Togruta.
Before its discovery by the Galactic Republic, Lola Sayu endured a cataclysmic event that obliterated its southern hemisphere, leaving a debris belt in orbit as its surface disintegrated over millennia. The cause of this event remained unknown. Despite its damaged state, the planet retained the ability to sustain life on its northern side and was discovered by the Republic by 522 BBY, who then decided to use Lola Sayu for a dark purpose.
In 522 BBY, the Republic partnered with the Jedi Order to establish the Citadel, a high-security prison designed to contain Jedi who had turned rogue or fallen to the dark side of the Force. This facility was built on the northwestern side of the planet, powered by geothermal energy. By 520 BBY, the Citadel was used to contain a fallen Jedi. Before the Clone Wars, information about the Citadel's pathways, including caves and tunnels, was recorded in the Jedi Archives of the Jedi Temple on Coruscant.
While the Republic controlled Lola Sayu for centuries, the planet's allegiance changed as it fell within the Confederacy of Independent Systems' territory during the Clone Wars. The confederate government launched an effort to take control of Lola Sayu, capturing the planet and Citadel. Recognizing the prison's value for containing and interrogating Jedi prisoners, the Separatists established a blockade of warships in orbit and placed a unit of battle droids under the command of Commander Osi Sobeck, a Phindian warden who equipped the Citadel with security measures like life-form scanners and anti-aircraft weaponry.
Sobeck commanded the Citadel with cruelty, torturing prisoners with EV-series medical droids. Aided by the T-series tactical droid K2-B4, Sobeck was proud of the Citadel's security and traps, such as electro-mines and wind conditions, preventing jetpack and grappling hook use. The Republic was prevented from obtaining reconnaissance of the facility due to Lola Sayu's capture, the blockade, and security measures, forcing the Jedi Order to use an unreliable map from the Jedi Archives.
Early in the Clone Wars, the Confederacy of Independent Systems seized Lola Sayu, giving them control of the Citadel. Jedi Master Even Piell was imprisoned there, carrying vital information. A strike team was sent to rescue him and his fleet officers, but their ship was destroyed. An entire fleet of Republic ships arrived to rescue them and the planet became a site of a large battle.
After the Clone Wars ended, a Separatist holdout remained on the citadel. The holdout was led by a malfunctioning droid that tried to follow its final directive.