Castilon was an ocean planet located in the galaxy's Mid Rim, and was located close to the borders of Wild Space. It was the homeworld of the Chelidae species and the Colossus—an aircraft refueling station, as well as a destination for racers—was located on Castilon, along with several other inhabited structures. During the Cold War between the New Republic and the First Order, Resistance Commander Poe Dameron sent the pilot-turned-spy Kazuda Xiono on a mission to Castilon. While Xiono was aboard the Colossus, the First Order forced its captain, Imanuel Doza, into allowing them to act as security, making way for them to occupy the platform and slowly take control. The Colossus was eventually forced to flee the planet in order to escape the First Order, rising from the ocean and jumping into hyperspace.
A terrestrial planet covered in vast oceans and dotted with isolated islands, Castilon was located in the Tashtor sector's Castilon system, within the Mid Rim, also falling in the region known as the Western Reaches, in grid square I-16 on the Standard Galactic Grid. The system had one star, and the planet itself was orbited by two moons. It had an atmosphere that was breathable to the various species that inhabited it, including humans.
Castilon was the homeworld of the Chelidae, a species of amphibian sentients who preferred to live above the water, and was also home to many non-sentient creatures, including both the avian speagulls and aquatic creatures such as the sharvo fish, snarlfish, and the massive rokkna. A number of smaller creatures lived in the oceans of the planet and were often the prey of the larger creatures, such as the speagulls. While most of the planet was covered in ocean, there were occasional inhabited structures above the surface of the water.
Over several millennia, a number of battles were fought over Castilon, leaving starship wreckage scattered across the seafloor. The space station and supertanker fuel depot Colossus was stationed on the planet, having sat partially submerged in Castilon's oceans since at least 14 ABY. The platform came to be owned by Captain Imanuel Doza, and fostered a vibrant racing circuit that became famous throughout the galaxy. Following the Battle of Endor, a battle was fought at the planet between the Galactic Empire and the New Republic, which resulted in a Star Destroyer being sent into the ocean. By 34 ABY, Doza lived in the Colossus' tower with his daughter Torra, his droid assistant 4D-M1N, and the pilots of Ace Squadron. The platform was frequently attacked by nearby pirates, though after the First Order betrayed them both crews had a common enemy.
Late in the Cold War, the First Order became interested in using the Colossus as a staging area. However, Captain Doza refused to place the platform under First Order control, although he did try to keep relations with them cordial. The First Order began staging pirate attacks against the platform, in an attempt to covertly pressure Doza into eventually inviting the First Order to act as security on the Colossus. At the same time, the Resistance, suspecting that the First Order had a spy on the platform, sent one of their own, the newly recruited Kazuda Xiono, on a mission to the Colossus to identify what the First Order wanted. Xiono was accompanied by Commander Poe Dameron's astromech droid, BB-8.
The First Order used the Warbird gang led by Kragan Gorr to attack the Colossus several times in an attempt to make Doza accept their proposal, but he remained reluctant. By kidnapping his daughter, the First Order convinced Doza to allow their presence, leading to an occupation of the Colossus platform, which continued to escalate. Civilian inhabitants of the Colossus who were once accepting of the First Order began to protest against the occupation. The First Order eventually targeted residents who opposed or defied their control, placing them under arrest to be sent offworld.
After the First Order discovered Xiono's true identity as a spy, he, along with Jarek Yeager and Neeku Vozo, planned to send a message out to the Resistance. To reach the First Order's communications jammer on Doza Tower, they coordinated with Captain Doza, sinking the platform almost entirely underneath the surface of the ocean. They successfully disabled the jammer, contacting General Leia Organa, who informed them that the Resistance was unable to provide assistance.
After expressing concern over the ethics and legality of the First Order's activities, Captain Doza was arrested by Commander Pyre, who took over the platform for himself. Xiono and Torra attempted to free the captured residents, but were interrupted when the First Order troopers on the platform stopped to witness Starkiller Base's destruction of Hosnian Prime.
While the platform's stormtroopers were watching the destruction via hologram, Xiono and Torra successfully freed Captain Doza, along with Yeager. With the help of Vozo, they let water into the Colossus to flush out the stormtroopers who were patrolling the corridors, sending them out into the planet's ocean. Losing control of the Colossus, Pyre decided to leave the planet, along with the First Order Security Bureau's Agent Tierny, who convinced Xiono's former friend Tamara Ryvora to join them. Before they could board their shuttle, Xiono ordered Vozo to activate the station's hyperdrive, lifting it up from the ocean.
The First Order abandoned the Colossus, sending TIE fighters to attack it. The Ace Squadron pilots were freed and sent to defend the station, along with Xiono and Yeager. The First Order sent a Resurgent-class Star Destroyer to assist in the battle, leading Xiono to give Vozo the coordinates to the Resistance base on D'Qar. As the Colossus was still within Castilon's gravity well and could not enter hyperspace, the station's defenders continued to hold off the First Order forces until it had ascended to a suitable height. Vozo activated the hyperdrive, but was unable to enter in the entire set of coordinates, and the Colossus escaped Castilon, heading to an unknown location in the galaxy.
The Star Destroyer remained on station above Castilon for a short time, during which Pyre and Tierny reported the Colossus' escape to Captain Phasma and received new orders to hunt down the station at all costs and Ryvora was formally inducted in as cadet DT-533, before departing on its search.
In order to help some residents of the Colossus who were feeling claustrophobic during the station's journey through space, Vozo set up a hologram projection of Castilon's sky in the station marketplace. Some time after the Battle of Crait, a First Order list of most wanted targets contained a number of names with their last known location listed as Castilon.
Later, in 35 ABY, Kazuda Xiono and Jarek Yeager returned to Castilon to rendezvous with Tamara Ryvora, who had seemingly defected from the First Order. The two arrived on the ocean world in their stolen First Order AAL transport, and they waited on a racing ring, something the Aces had used when the Colossus was at rest. After a while, three TIE fighters appeared in Castilon's cloudy skies. One of them was Tamara Ryvora, who, after a brief skirmish with the other fighters, joined Xiono and Yeager on the racing ring. After a reunion, Commander Pyre and Agent Tierny's Resurgent-class Star Destroyer appeared above the planet. It bombarded the surface, its powerful blasts pounding the ocean and creating large tidal waves. Xiono, Yeager, Ryvora, and CB-23 managed to get their ship out of Castilon's atmosphere, only to be captured soon after. During this, an unconscious Jace Rucklin discovered where the AAL had come from, the Barabesh system, meaning that the Colossus was there. After a while, the Star Destroyer left the Castilon system for the Barabesh system. It was later destroyed.
The Chelidae were a species native to the oceans of Castilon. An amphibious species, they were able to live underwater, though preferred to live on land. The Chelidae had their own language, but could understand Galactic Basic Standard, which was spoken by other inhabitants of the planet. Individuals of many other sentient species resided on board the Colossus, including the Chelidae, who worked as the platform's engineers.
The Colossus, an old supertanker fuel depot space station converted into a public refueling station, was one of the few inhabited structures on the planet, until it was forced to leave Castilon to escape the First Order. A number of smaller inhabited platforms and floating vessels were also located on Castilon. The Karavian Trench was located underneath the water, and was where Synara San salvaged a Clone Wars–era Z-95 Headhunter that contained the young rokkna Bibo.
Castilon first appeared in "The Recruit," the first episode of the television show Star Wars Resistance, which aired on October 7, 2018. It was first shown in the trailer for the series, and later identified on the Databank page for the Colossus.
Early concept art of the Colossus on Castilon was created by Polygon Pictures and released on the concept art gallery for "The Recruit" on StarWars.com. In the concept art, the Colossus is made up of several structures, and Castilon has landmass above the water.
The reference book Star Wars: Battles that Changed the Galaxy, places the Barabesh system is placed in two different regions of the galaxy. According to a map in the book, the Barabesh system is located in the Mid Rim Territories, but another section places it in the Outer Rim Territories. This appears to be related to the placement, by the Star Wars: Resistance episode The Recruit, of a ways out in the Outer Rim on the edge of Wild Space and its proximity to Barabesh system in which the space station Colossus hid. As the 2022 Star Wars Galaxy Map also places Barabesh and Castilon in the Mid Rim, this article assumes it to be the currently correct placement until clarified by Lucasfilm.
- Star Wars Resistance Racer