Grosmont Castle

Grosmont was raised in the wake of the Norman conquest of England, possibly by William FitzOsbern, 1st Earl of Hereford, to guard the route from Wales to Hereford. The first castle on the site was earth and timber, a keep and motte behind a palisade and ditch, with a borough established alongside it that became the village of Grosmont. FitzOsbern's landholdings in the region were broken up after his son Roger de Breteuil rebelled against the Crown in 1075, and by the early 12th century Grosmont belonged to the Anglo-Norman nobleman Pain fitzJohn.

A major Welsh revolt in 1135 prompted King Stephen to bring Grosmont back under Crown control together with its sister fortifications of Skenfrith and White Castle, forming the lordship known as the Three Castles. After a period of détente under Henry II in the 1160s, the De Braose and De Mortimer Marcher families attacked their Welsh rivals in the 1170s, provoking a Welsh assault on nearby Abergavenny Castle in 1182; in response the Crown spent £15 readying Grosmont over the next three years under the royal official Ralph of Grosmont, probably on its timber defences.

King John granted the Three Castles to his rising household official Hubert de Burgh in 1201, and Hubert began rebuilding Grosmont's hall in stone. Captured fighting the French in 1205, Hubert lost the castles to his rival William de Braose while imprisoned; John later dispossessed de Braose too, and de Braose's son seized the castles back amid the chaos of the First Barons' War.

Once free, Hubert rose to become royal justiciar and Earl of Kent, recovering the Three Castles in 1219 under Henry III. He rebuilt Grosmont's timber walls in stone and added three mural towers and a gatehouse, turning it into secure, high-status accommodation. Stripped of the castles again after his fall from power in 1232, Hubert saw them pass to the royal servant Walerund Teutonicus. In November 1233 Henry III camped an army outside Grosmont while campaigning against the rebel Richard Marshal, Earl of Pembroke; Marshal's night attack on the camp failed to take the castle but sent the King's army fleeing in confusion. Hubert was reconciled with the King the following year and the castles were returned to him.

Hubert fell out with Henry III again in 1239 and Grosmont reverted to Walerund, who completed a new chapel. The Three Castles passed to the future Edward I in 1254, and after Llywelyn ap Gruffudd's attack on Abergavenny in 1262, Grosmont's constable Gilbert Talbot was ordered to garrison it "by every man, and at whatever cost"; the threat passed without incident. Edmund, Earl of Lancaster, received the Three Castles in 1267, and they remained held by the earldom and later the Duchy of Lancaster for centuries.

Edward I's conquest of Wales in 1282 removed much of Grosmont's military purpose, and under Henry of Lancaster or his son Henry of Grosmont the interior was modernised in the first half of the 14th century into a suite of high-quality apartments set beside a deer park — the historian Jeremy Knight describes the castle of this period as "a small but very comfortable residence".

Grosmont's last military role came during Owain Glyndŵr's revolt: a battle near the castle in 1404 between the Welsh and Richard Beauchamp, Earl of Warwick, ended in an English victory, and the castle itself was besieged the following year by Owain's son Gruffudd before being relieved by a force sent by Prince Henry. By 1538 it had fallen into disuse; a 1563 survey found its bridge collapsed and its interior decayed, its building materials stripped or rotten though the outer walls stood, and a 1613 description called it "ruynous and decayed".

The Three Castles estates were sold in 1825 to Henry Somerset, 6th Duke of Beaufort, and in 1902 the 9th Duke sold Grosmont to Sir Joseph Bradney, a soldier and local historian. Evidence given to the Royal Commission on Ancient Monuments in Wales and Monmouthshire in 1909 described the castle as exceptionally well looked after. Frances Lucas-Scudamore placed it into state care in 1922, and conservation work followed, including clearing debris from the basement of the north block. Grosmont is now managed by Cadw, protected as a Grade I listed building and scheduled monument; its 14th-century north block, with its distinctive carved octagonal chimney, survives among the ruins.