The House of Korgath was a Klingon Great House, whose House fleet was used to conduct privateering operations on behalf of the Klingon Empire as early as the 2250s. (TOS video game: Starfleet Command: Orion Pirates)
The House of Korgath ambushed the RIS Bouteina with a K'vort Cha-class ship in the Synton system as part of an operation whose aim is to kill off the population of a planet afflicted by an ecological disaster caused by a volcano eruption. (RIS Bouteina: "If At First You Don't Succeed")
After that plan failed, the House hijacked a freighter full of dilithium and the bulk of the House's pirate fleet was defeated in a resupply run by a joint Romulan-Hydran effort. (RIS Bouteina: "Going, going, gone")
In 2389, on stardate 66150, the House of Korgath went so far as to plunder into Hydran territory, as a pirate ship belonging to the House has been captured near Deep Space I-94. (RIS Bouteina: "Hystelic Kingdom")
The House of Korgath still operated one carrier in 2415, plundering in ISC territory. The IKS Gomex'Zha was captured in an asteroid field. (Star Trek: False Vacuum: "Black Tornado")