 In 1825, the Three Castles estates were sold off to Henry Somerset, the 6th Duke of Beaufort.In 1902, Henry Somerset, the 9th Duke, sold Grosmont Castle to Sir Joseph Bradney, a soldier and local historian.Evidence was given to the Royal Commission on Ancient Monuments in Wales and Monmouthshire in 1909, stating that Grosmont was exceptionally well looked after.