Foss Castle

Has been described as a Certain Timber Castle (Motte Ringwork)

There are earthwork remains

NameFoss Castle
Alternative NamesLythe; Mulgrave; Fossards; Castrum de Mulgreit
Historic CountryYorkshire
Modern AuthorityNorth Yorkshire
1974 AuthorityNorth Yorkshire
Civil ParishLythe

Motte and bailey castle situated at the head of the valley of the Sandsend Beck, overlooking its precipitous gorge from the north side. The Barnby Beck, major tributary of the Sandsend Beck, issues over a series of waterfalls from a slack, while a minor tributary flows in a steep- sided gully along the western edge of the monument; because of its location the castle has good natural defences on its south-western side. The motte is an artificial mound, 50m in diameter at the base and surrounded by an 8m wide, 2m deep ditch. The mound is 4m high, the flat top being 40m in diameter and partially surrounded by a 0.5m high rampart bank. There are various low earthworks on the top of the mound, some of which will contain the foundations of buildings such as the fortified tower which once stood on the motte while other features are the result of a small-scale excavation reported to have been carried out prior to 1817. To the north-east of the motte and running at a tangent to it is a ditch which links the gully of the small stream to the west with the edge of the precipice to the south; the ditch is 5m wide and 1.5m deep at its north-western end but becomes 10m wide and 3m deep at its south-eastern end. The motte is flanked by two enclosures, or baileys. Of these, the northern one is triangular, measuring 60m by 30m across, bounded by the ditch on its north-eastern side and by the steep, 5m high scarp of the east bank of the stream at the west. The southern bailey is larger, measuring 65m long by 40m wide, bounded by the ditch to the north-east and by the precipice to the south and west. The castle was founded in 1072 by Nigel Fossard and abandoned about 1200 when Robert de Turnham built Old Mulgrave Castle, its stone successor, 700m to the east. (Scheduling Report)

Gatehouse Comments

The precursor to Mulgrave Castle. The later castle is on a ridge between two watercourses in a rather more prominent and defensible location. This castle is in the valley bottom, close to a mill and farm land. It appears as though this was an area of dispersed settlement so the Foss mill would have been a local focal point and the first castle seems to have been sited for administrative convenience rather than for defensive strength or elite hunting pursuits. The foundation date of 1092 given in the Scheduling report is both early and unusually precise. This does seem to be a ring-motte (a ringwork with a motte forming an integral part of the ring defence - Sometimes called a 'motte barrage' and considered an early feature by Bas Aarts. The site has a long folk lore history of early Saxon foundation and the likely Norman earthworks may be a rebuilding of an earlier Saxon centre. However, this seems quite a modest site considering it was the caput for at least 10 of Nigel Fossard's 105 manors.

- 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 ReferenceNZ831117
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  • Turner, Maurice, 2004, Yorkshire Castles: Exploring Historic Yorkshire (Otley: Westbury Publishing) p. 242
  • Jackson, M.J., 2001, Castles of North Yorkshire (Carlisle) p. 47 (plan)
  • Salter, Mike, 2001, The Castles and Tower Houses of Yorkshire (Malvern: Folly Publications) p. 65
  • Ingham, Bernard, 2001, Bernard Ingham's Yorkshire Castles (Dalesman) p. 19
  • King, D.J.C., 1983, Castellarium Anglicanum (London: Kraus) Vol. 2 p. 521
  • Renn, D.F., 1973 (2 edn.), Norman Castles of Britain (London: John Baker) p. 250
  • Sanders, I.J., 1960, English Baronies. A study of their origin and descent 1086-1327 p. 66-7
  • Illingworth, J.L., 1938 (republished 1970), Yorkshire's Ruined Castles (Wakefield)
  • Page, Wm (ed), 1923, VCH Yorkshire: North Riding Vol. 2 p. 390 online transcription
  • Armitage and Montgomerie, 1912, in Page, Wm (ed), VCH Yorkshire Vol. 2 p. 45
  • Young, G., 1817, A history of Whitby, and Streoneshalh abbey; with a statistical survey of the vicinity to the distance of twenty-five miles Vol. 2 p. 687 online copy


  • King, D.J.C. and Alcock, L., 1969, 'Ringworks in England and Wales' Château Gaillard Vol. 3 p. 90-127
  • I'Anson, W.M., 1913, 'The castles of the North Riding' Yorkshire Archaeological Journal Vol. 22 p. 348-51 (plan)

Primary Sources

  • Dugdale, William (Caley, J., Ellis, H. and Bandinel, B. (eds)), 1817-30 (originally pub. 1655-73), Monasticon Anglicanum (London) Vol. 1 p. 410


  • Constable, Christopher, 2003, Aspects of the archaeology of the castle in the north of England C 1066-1216 (Doctoral thesis, Durham University) Available at Durham E-Theses Online
  • Creighton, O.H., 1998, Castles and Landscapes: An Archaeological Survey of Yorkshire and the East Midlands (PhD Thesis University of Leicester) p. 607-8 online copy