Iron Age bivallate hill fort defended by a bank and ditch with the ditch measuring 16.4ft wide and 13ft deep. Medieval motte and bailey castle built within the defences, with the circular motte measuring 295.2ft in diameter and standing 80ft high. The surrounding chalk bank measuring 6.5ft high. Double bank and ditch enclosing the site.
500 BC c: Icini fort built.
1066 Soon after: Built either by Ralph Guader, Earl of East Anglia, or Roger Bigod, later Earl of East Anglia.
1173 Destroyed by Henry II.
1772 Eastern part of the site levelled.
1967 Field Investigation.
1998 Watching Brief.
2002 Watching Brief.