The Followers of Kahless was a religious order in Klingon society which venerated Kahless the Unforgettable. They were active as far back as the late 20th century when the Klingon people developed space travel and departed Qo'noS for the K'gah system in order to set up a monastery on the planet Boreth which Kahless had pointed to and prophecized that it would be the place of his return. (Decipher RPG module: Worlds)