The brek'tal ritual was a Klingon ritual that allowed the widow of an honorably slain Klingon, who was the head of his House, to marry his opponent. If the ritual was performed the victor then became the head of his slain opponent's house. The brek'tal was only allowed when the former leader of the house died without a male heir. Without the brek'tal the mistress, now widow, of the House may be granted special dispensation to lead the house on her own, but only if there were unique circumstances.
In 2371, Grilka, wife of Kozak, performed the brek'tal with Quark, a Ferengi, after Kozak died in a drunken fight with the barkeep. Leadership of Kozak's House temporarily passed to Quark before he ultimately got a divorce from Grilka and she took over its leadership. (DS9: "The House of Quark")