House Uller of Hellholt is one of the great noble houses in Dorne. Their keep, the Hellholt, is in the middle of the Dornish desert, and they are reputed to be impulsive and unpredictable. A Dornish saying is "Half of the Ullers are half-mad, and the other half are worse."
Their arms are rayonne yellow over crimson.
The Ullers were Andal adventurers who settled along the Brimstone. The Hellholt is named after an event in which rivals were invited to the castle, locked within, and burned to death. This action inspired the Uller's arms.
The Ullers supported House Nymeros Martell against House Yronwood during Nymeria's War. After the death of her first husband, Nymeria was married to Lord Uller and then to Ser Davos Dayne, her final husband.
At the start of the First Dornish War, Lord Harlen Tyrell's army found the Ullers had fled the Hellholt rather than give battle. When the Dornishmen rebelled later in the war, Harlen and his garrison disappeared in the sands after leaving the Hellholt to retake Vaith and Sunspear. Qheen Rhaenys Targaryen and Meraxes were both lost at the Hellholt in 10 AC. The queen's body was never recovered by the Targaryens, however, and some said she was tortured by the Ullers.