House Selmy of Harvest Hall is one of the principal noble houses of the Stormlands, holding their seat in the Dornish Marches among the fertile lands northeast of Nightsong. As marcher lords, the Selmys have long stood as a buffer between the Stormlands and the ancient rival kingdom of Dorne, defending the passes and valleys of the Marches against raiding from the south. Lords Selmy, Dondarrion, and Tarly were reckoned the great families of the Dornish Marches when they attended the Golden Wedding at King's Landing in 49 AC, a gathering that underscored the importance the crown placed upon the marcher houses.
The house's greatest renown came not from its lords but from a knight who was never meant to hold Harvest Hall. Ser Barristan Selmy, the eldest son of Ser Lyonel Selmy, was barely ten years old when he donned borrowed armor to joust as a mystery knight at the tourney of Blackhaven, where he was unhorsed and unmasked by Prince Duncan. His courage so impressed those in attendance that he was made a squire to Prince Duncan himself. Barristan went on to become one of the most celebrated knights of his age, named to the Kingsguard and eventually rising to Lord Commander, setting aside his right to inherit Harvest Hall to serve the Iron Throne. At the opening of A Game of Thrones, Arstan Selmy holds the lordship of Harvest Hall, a great-nephew of the famous knight.