By this time, however, St Briavels Castle had been in a slow period of decline for many years, similar to that of several other royal castles in the region, including Bristol and Gloucester.
Zu dieser Zeit aber befand sich St Briavels Castle viele Jahre lang in einer Phase des langsamen Niedergangs, ähnlich wie viele andere königliche Burgen in der Region, wie z. B. Bristol Castle und Gloucester Castle.