National Monuments Record Monument Type Thesaurus

The current most accepted classification is the National Monuments Record Monument Type Thesaurus for which the terms used for medieval fortifications are;

• Broadclass
• Defence;
  • Broad Term
  • Castle A fortress and dwelling, usually medieval in origin, and often consisting of a keep, curtain wall and towers etc.
    • Narrow Term
    • Adulterine Castle A castle erected without permission, i.e. without a royal licence to crenellate.
    • Artillery Castle Castles constructed between 1481 and 1561 for defence using heavy guns.
    • Concentric Castle A castle surrounded by two or more lines of walled fortifications.
      
    • Keep The major tower of a fortification, often acting as its last defence.
      
      • Shell Keep A Norman keep, in the form of a circular or polygonal enclosure surrounded by a wall.
        
      • Tower Keep A fortified keep in the form of a tower, used as a last refuge or defence. If a component of a larger site, use KEEP.
        
    • Keep And Bailey Castle A castle without a motte.
      
    • Motte An artificial steep-sided earthen mound on, or in, which is set the principal tower of a castle.
      
    • Motte And Bailey An early form of castle consisting of a flat-top steep-sided earthen mound, supporting a wooden tower, and a bailey.
      
    • Quadrangular Castle A castle built on a simple, rectangular plan, usually with a tower at each corner. This design became common in England after 1300.
      
    • Ringwork A defensive bank and ditch, circular or oval in plan, surrounding one or more buildings.
      
    • Ringwork And Bailey An enclosure within a bailey which contained a keep and sometimes took the place of a motte
      
    • Siege Castle A temporary castle built to house and protect troops besieging another castle or town.
  • Coastal Defence Site Sites, buildings and structures for the defence of the coastline from sea and air invasion.
  • Boom Tower (Use for Chain Tower) A tower at the mouth of the harbour to defend the end of the harbour boom.
  • Coastal Battery A defensive gun battery positioned to face out to sea to fire on enemy ships and amphibious craft.
  • Drawbridge Pit A purpose built pit, usually below a gatehouse or barbican, into which the counterweight of a drawbridge could be lowered, thus enabling the bridge to be raised.
  • Enclosed Settlement A site used primarily for domestic purposes on at least a semi-permanent or seasonal basis, and which has been surrounded by a bank and ditch, palisade, or some other form of enclosure. Use more specific type(s) where appropriate.
    • Burh An Anglo-Saxon fortified town or other defended site, not necessarily urban.
  • Fort A permanently occupied position or building designed primarily for defence.
    • Artillery Fort A fortified building or site with purpose built emplacements for artillery pieces.
  • Fortification A usually permanent defensive work. Use specific type where known.
    • Angle Tower A fortified tower found at the angle of a castle wall.
    • Artillery Tower A fortified tower designed to house a number of artillery pieces and a small garrison. Artillery towers first appear in England in the 16th century.
    • Bailey The courtyard of a castle, i.e. the area enclosed by the rampart or curtain. Use with wider site type where known.
    • Barbican Any earthworks, walling, bastion or fortified outwork, or combination of these, generally with ditch or moat.
    • Barmkin A defensive cattle enclosure added to fortified towers.
    • Bastion A flanking tower, or projection from the main walls of a defensive work from which a garrison can defend the ground in front or on the flank.
      • Bastion Outwork Earthworks and buildings added around a bastion to enhance protection of the bastion.
        • Ravelin In fortification, a detached triangular outwork consisting of two battered faces forming a salient angle. Usually positioned in the ditch in front of a rampart and between two bastions. Term mainly for military architecture from 15th century and later.
        • Redoubt A defence work, either a detached fieldwork or an outwork built as part of a fortification as a last defensive position.
    • Boom Tower A tower at the mouth of the harbour to defend the end of the harbour boom.
    • Bulwark Unspecified defensive structure like a mound of earth, a rampart, an embankment or a wall-like fortification. Also used as an early term for a bastion or blockhouse. Use more specific term where known.
    • Curtain Wall A wall between two towers or pavilions, usually surrounding a building, and often forming a major part of the defences.
    • Flanking Tower Small tower projecting from a castle wall, or other fortified wall. Allows defenders to fire along the length of the wall.
    • Gate Tower A tower, containing a gate, built into the walls of a town, castle or similar fortification
    • Hornwork An outwork joined to the mainwork by two parallel wings.
    • Interval Tower A tower situated above the rampart walkway and in between the angle towers along a defensive structure, such as a castle wall. They were used as lookout towers, roofed strongpoints or platforms from which missiles could be discharged or artillery fired.
    • Loopholed Wall A wall containing apertures to allow a weapon to be fired through it.
    • Postern A small gateway cut through the curtain wall or its flanking towers. Used primarily as an outlet for counter-attacking forces.
    • Rampart A protective earthen mound, often the main defence of a fortification.
    • Scarp The bank or wall immediately in front of and below the rampart.
    • Sconce A small protective fortification, such as an earthwork.
  • Fortified Bridge A bridge which is fortified at one or both ends.
  • Fortified Church Any church which bears signs of fortification. Churches on the Welsh and Scottish borders were often fortified, only allowing access to the tower from a single opening in the nave.
  • Fortified House A house which bears signs of fortification. These often include crenellated battlements and narrow slit-like windows
    • Bastle A fortified house of two or three storeys, the lower floor being used to house animals and the upper for domestic use.
    • Fortified Manor House A manor house, which was granted a royal licence to crenellate.
    • Pele Tower An uncrenellated, strong, fortified dwelling, of between two and four storeys. Occupied only in times of trouble built mainly in the border country of the North from the mid 14th to the 17th century.
    • Tower House A multi-storey, fortified hall house with one of the crosswings being raised in the form of a crenellated tower. Permanently occupied, they date from the mid 14th to the 17th century and are found mainly in the border counties of the North of England.
  • Frontier Defence A system of fortifications constructed along a national frontier to contain the local population, as well as keep out undesirable raiders e.g. Offa's Dyke. Use with more specific monument type where known.
    • Dyke (Defence) A defensive or boundary earthwork.
  • Town Defence Defensive fortifications such as ramparts, ditches and stone walls, built to defend a town or city.
  • Town Gate A highly defensible gateway, usually of stone with two or more storeys, built into the defensive walls of a town or city.
  • Town Wall A fortified wall surrounding a town or city.
• Domestic
  • Dwelling Places of residence.
    • House A building for human habitation, especially a dwelling place. Use more specific type where known.
      • Fortified House A house which bears signs of fortification. These often include crenellated battlements and narrow slit-like windows
        • Bastle A fortified house of two or three storeys, the lower floor being used to house animals and the upper for domestic use.
        • Fortified Manor House A manor house, which was granted a royal licence to crenellate.
        • Pele Tower An uncrenellated, strong, fortified dwelling, of between two and four storeys. Occupied only in times of trouble built mainly in the border country of the North from the mid 14th to the 17th century.
        • Tower House A multi-storey, fortified hall house with one of the crosswings being raised in the form of a crenellated tower. Permanently occupied, they date from the mid 14th to the 17th century and are found mainly in the border counties of the North of England.
    • Palace A substantial house in a town or the country (particularly associated with medieval London). Use more specific monument types where known.
      • Abbots Summer Palace An official residence of an abbot during the summer months.
      • Archbishops Palace The official residence of an archbishop, e.g. Lambeth Palace.
      • Bishops Palace The official residence of a bishop.
        • Bishops Summer Palace An official residence of a bishop used during the summer months.
      • Royal Palace A large, luxuriously appointed building used as an official residence by a member of royalty.
  • Great Hall A large communal room within a medieval building used for entertaining, eating and sleeping in.
  • Hunting Lodge A weekend retreat for Royal parties and others, when hunting in the Royal forests, or as a viewing station for the chase.

It can be seen that some of the definitions in this thesaurus are dated and debatable.