D'Ghor was the head of a wealthy Klingon Great House, House of D'Ghor and long-standing enemy of the House of Kozak. D'Ghor hoped to take over the House of Kozak but did not wish to risk destroying it by challenging them openly. Instead, from 2366 to 2371, he began systematically attacking the House's financial assets, weakening the house financially.
When Kozak, the head of the House died in an accident in 2371, apparently killed in self-defense by a Ferengi named Quark, D'Ghor traveled to Deep Space 9 posing as Kozak's brother to learn the truth. Quark maintained his story that he had killed Kozak. Since Kozak had apparently died in personal combat and not under unusual circumstances, it prevented the possibility of allowing Kozak's widow Grilka from taking over the House and would allow D'Ghor to take over.
Grilka worked to prevent this by marrying Quark, causing her house to become the House of Quark. Quark then brought evidence before the Klingon High Council of D'Ghor's financial attacks. D'Ghor, in response, challenged Quark to a fight to the death.
Quark refused to defend himself, knowing that he couldn't possibly defeat D'Ghor, making it nothing more than an honorless execution. D'Ghor was prepared to strike Quark down anyway when Chancellor Gowron intervened, accusing D'Ghor of having no honor. D'Ghor suffered an immediate discommendation and was ejected from the council. By contrast, Quark was commended as a Ferengi of unusual bravery. (DS9: "The House of Quark")