House Dondarrion is a minor house from the Stormlands, sworn to House Baratheon of Storm's End. They were the lords of Blackhaven, controlling the entrance to the Boneway, the path from the Stormlands to Dorne.
The head of House Dondarrion at the time of A Game of Thrones was Lord Beric, who was engaged to Lady Allyria Dayne. He was commanded by the hand of the king, Eddard Stark, to hunt down the fallen knight Gregor Clegane, who was wreaking havoc in the Riverlands. After being killed in an ambush and resurrected by the red priest Thoros of Myr, he served as head of the Brotherhood Without Banners. Lord Beric shed his past as a lord and eventually died to save Lady Catelyn Stark.