The Boreth monestary.
The Clerics of Boreth are a group of religious people within Klingon society who lived on the planet Boreth in the Klingon Empire.
The Clerics, led by the High Cleric, have a special place in their society for they watch over the planet that Kahless the Unforgettable said he would return in The Story of the Promise. As such, the Cleric's serve to guide the spiritual heart of the Empire and maintain the ideals that Kahless brought to his people during the Mythic Age. The Clerics would also watch over sacred scrolls and were privey to information that the everyday Klingon did not know such as how Kahless made the first Bat'leth. They would also watch over meditating Klingon's and determine whether they had recieved a vision from Kahless.
The Clerics, after worrying signs of discontent and threat of civil war in the Empire, decided to create a clone of Kahless, made from DNA that was available on several artefacts. However, their deception was discovered by Lieutenant Commander Worf, Son of Mogh, but it was agreed that the clone remain as the figurehead of the Empire.
(TNG: Rightful Heir)
Their deception did not seem to damage their position as later, Worf wished to once again join the Clerics of Boreth when he contemplated leaving Starfleet.