|Grosmont Castle||South Wales|
|Grosmont, Abergavenny, Monmouthshire||CADW|
Grosmont Castle, along with Skenfrith and White, is one of three castles built to protect one of the main routes through the border region between England and South Wales. In the late 1130's King Stephen brought all three castles together under a single Lordship that controlled the 'Three Castles' as one defensive unit.
In the early 13th century Hubert de Burgh held the lordship of the Three Castles. He built modern stone castles at Skenfrith and Grosmont. The name Grosmont is derived from the French 'gros mont' meaning 'big hill', an apt name for the large mound that the castle is built on. Hubert built a large hall on the east side of the mound and on the other sides he constructed a curtain wall built in straight sections, connected by semi-circular towers on the angles.
In 1267 the Three Castles were granted to Edmund 'Crouchback', earl of Lancaster. Although all three castles were maintained only Grosmont was used as a home, and during the 14th century the Lancasters remodelled the buildings around the inner ward to make accommodation more suitable for a noble household. The south-west tower was reconstructed, with three storeys of comfortable apartments and the northern tower was demolished to make way for two rectangular blocks housing suites of apartments. The tall octagonal chimney which served its fireplaces is the most impressive remnant of these buildings.
In 1404-5, during a Welsh revolt led by Owain Glyn Dwr, the castle played its last military role. In 1404 the Welsh were defeated in battle on Campston Hill near Grosmont, but the following year they returned and laid siege to the castle. A relief force was sent from Hereford by Prince Henry, the future King Henry V, and the Welsh were defeated. The castles were no longer the homes of nobility and by the 16th century all three castles had been abandoned and were falling into ruin.