A Klingon friend of the House of Mogh who took in the infant Kurn when the family left for Khitomer and raised him as his own son, concealing his true parentage.
Lorgh was a trusted friend of Mogh. When Mogh travelled to Khitomer in 2346 he expected to be away only briefly and left his younger son Kurn, barely a year old, in Lorgh's care. After the family was believed wiped out in the Romulan attack, Lorgh brought the boy up as a member of his own house and told nobody whose child he was.
Kurn explains this history to Worf in The Next Generation episode Sins of the Father. Lorgh revealed the truth only when Kurn reached the Age of Ascension, and it is because the High Council does not know of Kurn's existence that he is able to stand beside Worf as his cha'DIch without sharing openly in the family's disgrace.
Lorgh is never seen on screen.