The Grehollo system existed within the Manoe sector of the Mid Rim region. Within this system were the Imperial installation, the Grehollo station, and the moon called Captivity. Due to the severe environment of Captivity, the Empire utilized it as a place to exile prisoners, with TIE fighters originating from the Grehollo station constantly patrolling the [prison](/article/prison/legends] moon.
During the Galactic Civil War, the Rebel Alliance undertook a mission directed at the Grehollo system. A Rebel soldiers group infiltrated the moon disguised as exiles and discovered a collection of political prisoners of great value to the Alliance's cause. Subsequently, the freighter named the Millennium Falcon extracted both the Rebel team and the prisoners from Captivity, escaping the Grehollo system entirely.
The location of the Grehollo system was within the Manoe sector, which itself was a part of the New Territories section of the Mid Rim. Inside the Grehollo system existed the small terrestrial moon named Captivity, along with the Grehollo station, a military installation belonging to the Galactic Empire. The surface of Captivity was covered by a layer of clouds and was frequently battered by intense storms, and its terrain consisted of tall mountains alongside sharp, uneven rock formations. The dangerous environment of Captivity made landing a starship there a very risky undertaking.
The Grehollo system was also home to a prison planet.
The prisoners that the Galactic Empire wanted to keep alive, for various reasons, were exiled to Captivity. These prisoners were launched in escape pods to the surface of the moon, while Imperial TIE fighters from the Grehollo station performed constant patrols over the moon.
During the Galactic Civil War, the Rebel Alliance launched a mission to rescue political prisoners on Captivity, who were valuable to the Alliance's cause, including exiled Imperial senators. A team of Rebel soldiers, pretending to be the leadership of Virujansi, a planet that had been recently taken over by the Empire, were able to convince Imperial Major Lariss, the leader of the Imperial forces on Virujansi, to exile them to Captivity. After they arrived on the moon, the Rebel soldiers located the prisoners, and the freighter Millennium Falcon eventually extracted both groups, transporting them out of the system.
Several groups of prisoners inhabited the moon Captivity, including some who were Human. Eventually, the criminal gang led by Andews Rolo wiped out all of the other groups, with the exception of a smaller group of political prisoners who were led by former Imperial Navy captain Dedelin.
The roleplaying game adventure "To Free the Forgotten," which was published in the 1989 The Star Wars Rules Companion for use with Star Wars: The Roleplaying Game by West End Games, was the first appearance of the Grehollo system. Greg Gorden wrote the adventure, basing it on a story by Steve Gilbert and Michael Stern. In "To Free the Forgotten," the game-masters are encouraged to create their own details regarding the Rebel escape from the Grehollo system. This article assumes the adventure plays out as described.
The sector of the same name contained the Grehollo system in "Twinkle, Twinkle Little Star, How I Wonder Where We Are," a 1990 roleplaying game source article that was published in Voyages SF 13. Since the Lucas Licensing process did not release the article, its canonicity within the Star Wars Legends continuity was never established. Instead, the StarWars.com Online Companion to the 2009 reference book The Essential Atlas placed the Grehollo system, and therefore Captivity, in grid square K-7 as part of the Manoe sector. Jason Fry, who co-authored The Essential Atlas, stated on the Jedi Council Forums of TheForce.net that the Manoe system was made for "bookkeeping purposes" so that every sector listed in the Online Companion would have at least one corresponding system, although Grehollo was also placed in the Manoe sector.