The motte and bailey castle built at Arundel by Roger of Montgomery, Earl of Shrewsbury, in the late 11thc., would have contained mainly wooden structures, although the stone gatehouse is believed to date from that period. In the second half of the 12thc. (c.1170-1190) the circular shell keep was erected, the curtain walls were strengthened and the domestic quarters extended. The castle was ruined during the Civil War, and was largely rebuilt in the late 19thc. (C A Buckler; 1890-1903). This work included the neo-Norman Postern Gate.
The doorway of the keep dates from the second quarter of the 12thc., and the surviving S window of the hall from the late 12thc. A beakhead fragment recorded some years ago is now lost. However, a number of carvings, including a second beakhead voussoir, were discovered during an extensive restoration of the castle in 1976-78. These are now displayed in the Fitzalan Chapel. In addition, a carved voussoir is set in the restored face of the E curtain wall.