St Briavels Castle is a moated Norman castle at St Briavels in the English county of Gloucestershire. The castle is noted for its huge Edwardian gatehouse that guards the entrance. St Briavels Castle was originally built between 1075 and 1129 as a royal administrative centre for the Forest of Dean. During the 13th century the castle became first a favourite hunting lodge of King John, and then the primary centre in England for the manufacture of quarrels, large numbers of which were required for crossbows in medieval warfare. The castle was transferred many times between royal favourites in the 14th and 15th centuries and slowly declined in appearance and importance. St Briavels Castle became used primarily as a court and as a notorious debtors' prison, conditions being documented by the p