Motte and two baileys dating from 1068. Besieged for 3 months in 1102. Shell keep of Caen stone dates from circa 1138. Also remains a gatehouse and a C13 barbican and curtain wall. The castle was subjected to a 'unfeeling' rebuild in 1791-1815, which replaced sections destroyed in the civil war and altered many of the surviving buildings. Lower part of gatehouse possibly late C11, built for Roger de Montgomery, who was granted Arundel by William the Conqueror. Middle stage of gatehouse, keep, and cellars under south-east range appear (stylistically) to date from late C12; possibly from tenure of Earl William de Albini. Barbican, upper stage of gatehouse, north-west buttress, and well tower to keep, appear (stylistically) to date from late C13, possibly from time of Richard, 1st Earl of Arundel, who received the grant of a fair to help repair the castle. Curtain and towers round north end also mediaeval, but of uncertain date, and restored in late C19. (Listing report)
Arundel Castle survives well despite the slighting and rebuilding of some of the castle buildings after the Civil War. It is of an unusual twin bailey plan, illustrating the wide range of possible forms of this class of monument. The castle is well documented historically and the long history of its use and adaptation is well illustrated by a wide range of surviving features such as the Norman gatehouse and keep, the curtain wall, outer bailey and Civil War defences. These features also considerably enhance the castle's significance because they provide important information on a number of key stages in the history of defensive fortification.
The monument includes a motte and bailey castle at its centre, the outer bailey area to the north-east, the square earthwork known as the bowling green and the fishponds on the eastern side of the castle grounds