At the time, a General known as K'Trelan had risen from the ranks and intended to displace the Emperor. He was successful and he managed to purge the Imperial court of Reclaw's followers. However, only one of these members of the old court survived - a blademistress known as Hal'korin who led the QawHaq'hoch who managed to flee with her followers to a hidden sanctuary. In order to track them down and eliminate them, the new Emperor K'Trelan selected his most faithful followers with this task. Forming a group of their own known as the Warriors of Gre'thor, they engaged in a campaign to eliminate their mortal enemies - a task that they continued to commence across the centuries all the way to the 24th century where they remained as a secret society within Klingon culture. They were successful in killing twelve of the corps leaders of the qawHaq'hoch and claimed their special bat'leths which were needed to find that secret orders sanctuary.
In 2378, the qawHaq'hoch abducted Miral Paris as they believed her role as the Kuvah'magh was to be fulfilled. In order to track her daughter down, B'Elanna Torres met with Emperor Kahless who revealed to her the history of both the qawHaq'hoch and the Warriors of Gre'thor. He also signalled the Warriors of Gre'thor in order to enlist their aid in tracking down the qawHaq'hoch. (VOY novel: Full Circle)
- Presumably, the group is named after the Klingon afterlife known as Gre'thor.