Bramber Castle was founded by William de Braose as a defensive and administrative centre for Bramber, one of the six administrative regions ? each of which was controlled by a castle ? into which Sussex was divided following the Norman Conquest. It was held almost continually by de Braose and his descendants from its foundation by 1073 until 1450.
One of these descendants, another William de Braose, was among those barons suspected of disloyalty to King John in the early 13th century. The king demanded William?s two sons as hostages. Lady de Braose refused, saying she would not trust her sons to a man who had already murdered his own nephew. The castle was confiscated by the king and the family captured. Lady de Braose and her two sons died of starvation while imprisoned at Windsor Castle.
King John held Bramber Castle only briefly but is known to have carried out repairs to the buildings. Later the castle passed back to the de Braose family, who held it until the 14th century, and then to the Mowbray family.