The Kromnoth sector was a region of space, a sector located in the galaxy's Beta Quadrant. It lay coreward from the Klingon Empire in the 22nd century, and was conquered by the Klingons during the Ware crisis. (ENT - Rise of the Federation novel: Live by the Code)
History and specifics[]
On September 19, 2165, the captured Klingon privateer Klorek revealed to the Klingon High Council in Qam-Chee on Qo'noS that the QuchHa's Ware fleet stemmed from the Partnership of Civilizations, found beyond the Kromnoth sector. (ENT - Rise of the Federation novel: Live by the Code)