St Briavels Castle is a moated Norman castle at St Briavels in the English county of Gloucestershire.
St Briavels Castle seems to have been built before 1128, probably by William Fitz Baderon, the lord of nearby Monmouth. On William’s death King Henry I seized the castle and garrisoned it for the crown. In 1141 his daughter, the Empress Matilda gave the castle with the Forest of Dean to Miles de Gloucester, 1st Earl of Hereford. Miles’ son, Roger Fitzmiles, 2nd Earl of Hereford lost the castle to King Henry II in 1155. By this stage the castle appears to have consisted of a square keep and curtain walls. Certainly the following kings only spent minimal money on the castle’s upkeep.
Between 1209 and 1211 King John had the much of the internal buildings of the castle constructed. Some of these are still in use as a Youth Hostel run by the Youth Hostels Association. In 1292-93 the new gatehouse was built with twin round towers by order of King Edward I. During the disturbances of the reign of King Edward II an extension was made to the castle called ‘the Peel’. The castle remained in occupation quite late as it proved important to the running of the Forest of Dean, acting as the headquarters for the Forest’s Constable, and the centre of the royal industry of supplying arrow-heads to the Tower of London. The keep only collapsed in 1752. The name of the castle and the village stems from that of Saint Briavel.