A Klingon Great House left without a male heir when its drunken head Kozak died in Quark's bar, briefly becoming the House of Quark before passing to his widow Grilka.
The House of Kozak is at the centre of the Deep Space Nine episode The House of Quark. Its head, Kozak, falls on his own knife during a drunken quarrel in Quark's bar, and Quark boasts that he killed him in single combat to drum up business.
The lie has consequences. Kozak's enemy D'Ghor has been quietly ruining the house and expects to absorb it, since an accidental death leaves no heir. His widow Grilka abducts Quark to Qo'noS and marries him at knifepoint, making the Ferengi head of the house, and Quark's audit of the family finances exposes D'Ghor's dishonourable methods.
Before the High Council, Quark refuses to fight a duel he cannot win, and Gowron has D'Ghor cast out for being ready to kill an unarmed man. Grilka is granted special dispensation to lead the house herself and gives Quark a divorce. She returns in Looking for par'Mach in All the Wrong Places.