South Mimms Castle

Has been described as a Certain Timber Castle (Motte)

There are earthwork remains

NameSouth Mimms Castle
Alternative NamesSouth Mymms; castle on the Lea; Super Lviam
Historic CountryLondon and Middlesex
Modern AuthorityHertfordshire
1974 AuthorityHertfordshire
Civil ParishPotters Bar

Castle comprising a 9m high motte in the NW corner of a kidney-shaped bailey 390' x 350'. There are traces of an outer bailey to the S, now ploughed. There has been extensive lime-quarrying to the W of the monument; the quarry is now infilled and planted.

Excavations revealed that the construction and finds were consistent with the assumption that the castle was built by Geoffrey de Mandeville in 1141 with a charter from Matilda, and was possibly destroyed in 1143. It is also possible that earlier manorial buildings were demolished when the castle was built. The 'motte' is unusual, but not unique, in its construction and purpose. The timber tower was built first, and earth built up around its base to ensure stability, with access into the tower through a timber-lined tunnel. The visual result was not one of a raised mound within the bailey (Davidson).

Finds of 13C/14C material in the vicinity suggest some form of later occupation on the site. (Hertfordshire HER)

Gatehouse Comments

It may well be that the motte at South Mymms is unusual purely in being fully excavated but that in practice this form of work, a timber revetted mound of earth supporting a tower or house, was a more normal form. In a field trip with the Castle Studies Group in 2010 Davidson reports that he knew of 23 mottes which had excavated sufficiently for the form to known and of these 20 were the timber revetted type (although sometime in layers of revetments. See also the Bayeux tapestry portrayal of the motte at Bayeux; Hertford Castle, Hertfordshire; Luton Holly Lodge, Bedfordshire). However, if it were Hertford there seem no reason it would not be called Hertford and much the same could be said about a castle in Luton. The site at Bow is dubious as a castle site. South Mimms is clearly a castle of the right date and in roughly the right place, although not somewhere of such significance as to be clearly known by name. It is not, however on the River Lea which is a few miles to the east, although it is on a small tributary. The conjecture that this is Geoffrey's castle is entirely reasonable but not certain. The village of South Mimms has moved location since the C12 and the castle was not isolated when first founded

- Philip Davis

This site is a scheduled monument protected by law

Not Listed

Historic England (PastScape) Defra or Monument number(s)
County Historic Environment Record
OS Map Grid ReferenceTL229026
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  • Clark, J. 2014, ''Playing the stag' in medieval Middlesex? A perforated antler from South Mimms Castle – parallels and possibilities' in K. Baker, R. Carden and R. Madgwick, Deer and People (Oxford: Windgather Press) p. 208-215
  • < >Kent, John, Renn, Derek and Streeten, Anthony, 2013, Excavations at South Mimms Castle, Hertfordshire 1960-91 (London and Middlesex Archaeological Society Special Paper 16) < > (The long awaited final report of the 1960's excavation)
  • Osbourne, Mike, 2012, Defending London (Stroud: The History Press) p. 28
  • Goodall, John, 2011, The English Castle 1066-1650 (Yale University Press) p. 76
  • Purton, P.F., 2009, A History of the Early Medieval Siege c. 450-1220 (Woodbridge: The Boydell Press) p. 271
  • Salter, Mike, 2002, The Castles of The Thames Valley and The Chilterns (Malvern: Folly Publications) p. 48
  • Pettifer, A., 1995, English Castles, A guide by counties (Woodbridge: Boydell Press) p. 154 (slight)
  • Coulson, Charles, 1994, 'The Castles of the Anarchy' in King, Edmund (ed.), The Anarchy of King Stephen's Reign (Oxford University Press) p. 87n39
  • Higham, R. and Barker, P., 1992, Timber Castles (Batsford) p. 279-80, 356
  • King, D.J.C., 1983, Castellarium Anglicanum (London: Kraus) Vol. 1 p. 269-70, p. lxvi
  • Fry, P.S., 1980, Castles of the British Isles (David and Charles) p. 300
  • Baker, T.F.T. (ed), 1976, 'South Mimms: Manors' VCH Middlesex Vol. 5 p. 282 online transcription
  • Renn, D.F., 1973 (2 edn.), Norman Castles of Britain (London: John Baker) p. 314
  • Renn, D.F., 1971, Medieval Castles in Hertfordshire (Chichester; Phillimore) p. 20-1 (plan)
  • 1960, The Archaeologist in Essex, Hertfordshire, London and Middlesex 1959 (CBA Group 10) p. 31-4
  • RCHME, 1937, An inventory of the historical monuments in Middlesex (HMSO) p. 95 no. 2 online transcription
  • Round, J.H., 1892, Geoffrey de Mandeville (London: Longmans) p. 168, 174-5 online copy


  • Coulson, C., 1994, 'Freedom to Crenellate by Licence - An Historiographical Revision' Nottingham Medieval Studies Vol. 38 p. 104n50
  • King, D.J.Cathcart, 1972, 'The Field Archaeology of mottes; Eine kurze übersicht' Château Gaillard Vol. 5 p. 101-112
  • Kent, J.P.C., 1968, 'Excavations at the motte and bailey Castle of South Mimms, Hertfordshire, 1960-67' Barnet and District Local Historical Society Bulletin Vol. 18
  • Davison, B., 1967, 'The origins of the castle' Current Archaeology Vol. 5 p. 130
  • 1965 Oct, Bulletin of the London and Middlesex Archaeological Society Vol. 12 p. 3
  • Kent, 1964, CBA Group 10 Vol. 22 p. 10-11
  • 1964, Medieval Archaeology Vol. 8 p. 255 download copy
  • (Kent), 1962-3, Medieval Archaeology Vol. 6-7 p. 322 download copy
  • (Kent), 1961, Medieval Archaeology Vol. 5 p. 318 download copy
  • Thompson, M.W., 1961, 'Motte Sunstructures' Medieval Archaeology Vol. 5 p. 305-6 online copy
  • Renn, 1957 Nov., 'South Mymms castle' Barnet and District Record Society Vol. 10
  • Davis, C.L., 1933-7, 'The Norman Castle of South Mymms' Transactions of the London and Middlesex Archaeological Society Vol. 7 p. 464-71 download copy
  • Sands and Dennon, 1933-7, 'South Mymms Castle Excavation Committee' Transactions of the London and Middlesex Archaeological Society Vol. 7 p. 175-9 download copy

Primary Sources

  • Cronne, H.A. and Davis, R.H.C. (eds), 1968, Regesta Regum Anglo-Normannorum Vol. 3 p. 99-103 online copy


  • Davidson, Brian, 2010, Castle Neroche site visit with Castle Studies Group.
  • Isobel Thompson, 2005, Extensive Urban Survey - Hertfordshire (English Heritage) Download copy