The Zealots of Psusan comprised a religious cult that held sway over three colonies situated along the Talcene Transit hyperspace route. Devotees of this belief system willingly offered substantial prices to acquire root sections and mineral water that were derived from the bubse trees unique to the planet Saleucami, and then traded as specialized medicinal exports.
In the year 22 BBY, during a period of rapid expansion for the cult, Agira Nyrat, a tattooed human adherent, made an appearance at the Outlander Club located on the planet Coruscant, where she pinpointed a weak-minded individual suitable for conversion. By 1 BBY, the Zealots of Psusan had become an established faith and were among the numerous religious organizations that regarded the moon Jedha as sacred, with members undertaking pilgrimages to this lunar location.
A member affiliated with the Zealots of Psusan initially emerged in the prequel trilogy movie Star Wars: Episode II Attack of the Clones, which premiered on May 16, 2002. Within the current Star Wars canon, the cult's official identification occurred in "Visiting Saleucami," an article featured by De Agostini within the "Guide to the Galaxy" section of the magazine Star Wars: Build the Millennium Falcon 44 around November 4, 2015. The Zealots were initially part of the Star Wars Legends continuity, where they received their first mention in Star Wars: Attack of the Clones: The Visual Dictionary, authored by David West Reynolds and published before the film's release on April 23, 2002.