House Qoherys of Harrenhal was a short-lived noble house of Valyrian blood, raised up by Aegon the Conqueror in the second year After the Conquest to hold the great burnt castle of the riverlands. Ser Quenton Qoherys had served Aegon long and faithfully as master-at-arms at Dragonstone, training the king's brothers and his sons at sword and lance; when Harren the Black and all his line perished in the dragonfire that took Harrenhal, Aegon gave the ruined keep and the rivers about it to his old retainer in reward, that a Targaryen man might watch the heart of the Trident in the king's name.
Lord Quenton did not long enjoy his lordship, and his grandson Gargon, called the Guest for his fondness for sitting at the tables of his bannermen and exercising the lord's right of the first night with their daughters, was even less suited to the great castle. In the reign of King Aenys I a brigand who named himself Harren the Red — claiming, as such brigands will, to be a grandson of Harren the Black — descended upon Harrenhal at the head of his bandit company, took Gargon while he was at supper in a vassal's hall, and gelded him and slew him there in payment of all the grievances his bannermen had borne. With Lord Gargon died the last of the Qoherys, and King Aenys handed the cursed castle on to House Harroway, who would hold it scarcely longer than the Valyrians had.