Glossary of Terms used in Military Architecture

ABATTIS, ABATIS, a continuous thick line of felled trees and shrubs driven into the ground with bows pointing outwards to form an impenetrable obstacle. It was also constructed in shallow water to impede the movements of boats towards the shore.

ABUTMENT, an end wall supporting a row of casemates.

ACROPOLIS, an elevated stronghold of a Greek city, usually containing the temple of the patron divinity within its walls.

ADVANCED WORKS, ouvrages avancée - f., defensive works placed beyond the glacis but still near enough to be covered from the main defences.

AIR-HOLE, a ventilating hole, usually above a musketry loophole or embrasure, to extract smoke, especially from inside casemates or musketry galleries.

ALBARRA, detached wall tower designed to allow for better flanking fire and also to be easily isoalted from the main defences if taken by the enemy; a peculiarity of Iberian castles.

ALCAZAR, a Moorish or Spanish castle or fortress.

ALURE, a gallery or passage along the parapet of a castle.

ANTEMURAL, a wall or outerwork surrounding and protecting a castle; in some late medieval documents the word barbican was used to denote an antemurale.

ARCH, a curved construction spanning an opening.

ARRIS, the sharp edge produced when to surfaces meet together as at the salients of bastions or spurs.

ASHLAR, squared building masonry used in the construction of walls and other structures.

AVANCEÉ, a place-of-arms placed where the road leaves the covertway after passing through the gate.

AVANS MUR, see antemural.

BAILEY, the open area or courtyard within a medieval castle. (see motte-and-bailey).

BALISTRARIA, a loophole or aperture in medieval battlements through which crossbowmen fired their weapon.

BANQUETTE, a raised walkway, sometimes stepped, behind a high  parapet to enable troops to fire their weapons over the parapet.

BARREL VAULT, a continuous arched roof of stone, of semicircular section, supported by parallel walls.

BARBETTE, a barba - í., en barbette - f:, a platform on which guns are mounted to fire over a parapet.

BARBICAN, BARBACAN, an outer work defending the gate of a castle or citadel, frequently a fortified gate house.

BARRACK BLOCK, building, sometimes bombproof and fortified, designed to house the garrison of a fort.

BARTIZAN, a battlemented turret projecting outwards from the corner of atower or wall.

BASCULE, a counterbalanced drawbridge of which there are two main types, the drawbridge levered by pole-arms or a counter-balanced gangway.

BASTION, Bastione, beluardo - i., a work pro ecting outwards from the main wal~s of a defensive enceinte, designed to enable the garrison to see and defend the adjacent perimeter together with the area in front of the ramparts. In its embryonic form, the bastion can be found in both cylindrical and polygonal form. The polygonal form was perfected by the Italian engineers of the late 15C and early 16C into a pentagonal work composed of two faces, two flanks and a gorge.

BASTIONETTE, a small bastion added to the salient of a bastion to provide enfilading fire along the two faces of the latter.

BATARDEAU, a dam or wall across a moat or ditch, built with a sharp ridge to prevent enemy troops from crossing the place; sometimes fitted with a turret as an additional barrier.

BAULKS, the beams on which the planks of a bridge spanning a ditch rest. BATTER, the inward inclination of the face of a wall from the vertical; a battered wall recedes as it rises.

BATTERY, a platform, usually protected by a parapet, for cannon and mortars; orillion battery, a battery placed in the flank of a bastion and sheltered by the orillion; coastal battery, a work, sometimes fortified against direct assault, designed to engage enemy ships close to the shore.

BATTLEMENT, a fortified parapet with merlons and crenels, or embrasures.

BAYOU, a trench in the rear of a battery designed to allow communication with a magazine; a branch of a trench.

BERM, a ridge below a parapet.

BLOCKHOUSE, a small fortified work consisting of one or more rooms fitted with loopholes in its sides to permit defensive fire in various directions.

BONNET, a small counterguard in front of the salient angle of a ravelin.

BONNETTE, an increase in height given to a parapet due to the upward prolongation of its exterior and interior slope.

BONNET DE PRETRE, a defensive work resembling a tenaille.

BOULEVARD, Boulevart - f., a substantial defensive work, usually polygonal in plan, projecting outwards from the main enceinte; an early bastion-like structure.

BRATTICE, a temporary breastwork, parapet or gallery of wood used during a siege.

BRAYE, Braga - i., a continuous outerwork protecting the main enceinte, placed inside the ditch and separated from both the scarp and counterscarp walls.

BREACH, Breccia - i., a gap blown open in the walls of a fortress by a mine or artillery fire.

BREASTWORK, a fieldwork thrown up breast-high for defence; a parapet.

BRISURE, a break in the line of a curtain wall in order to increase the area for guns in the flank of a bastion and to allow for a wider view and field of fire from the same.

BULWARK, Bollwerk - g., Bolverk - s, meaning a log-work, a substantial defensive work of earth; referring also to early bastion-like works of polygonal or semicircular plan (Boulevard, Beluardo), usually detached from the main enceinte.

BUTTRESS, a mass of masonry built against a wall to give additional lateral strength; usually to counteract the lateral thrust of a roof, vault or arch.

CAPANATTO, a masonry loopholed room for defenders, usually with a triangular front and opened towards the interior of the fort.

CAPITAL OF THE BASTION an imaginary line bisecting the salient angle

CAPONIER, a sheltered defensible passage across the ditch of a fort or cut through the glacis, linking the outerworks to the main enceinte; sometimes used to provide additional flanking fire along the ditch.

CASEMATE, cassamatta - i., a vaulted chamber built in the thickness of the ramparts and used as a barrack or gun position (firing through embrasures).

CASEMATED RETRENCHMENT, a retrenchment fitted with guns firing through embrasures from within vaulted casemates and placed behind the main line of fortification.

CASTLE, a stronghold or fortified post, more specifically the fortified residence of a prince or feudal lord.

CASTRUM, a term originally used to refer to a Roman military camp but later also used to refer to early medieval castles,

CAVALIER, a raised earth platform, built on a bastion or curtain wall, designed to mount artillery and to command the surrounding ground.

CHEMIN DE RONDE, a continuous passage or walkway on a rampart, protected by a parapet, designed to allow the defenders access to the various works along the defensive trace.

CITADEL, Cittadella - i., a fortress or castle built to dominate or protect a town. COPING, a sloped or bevelled stone cap placed on top of a parapet or wall so as to protect the masonry and infil below from the penetration of water from above.

CORBEL, a small projecting stone designed to support a beam or other horizontal member such as a machicolation.

CORDON, a rounded stone moulding or string-course, below the parapet of the revetment of a rampart, usually going all round the fort.

CORNICE MOULDING, a ~ moulded projection forming the exterior trim of a wall.

COUNTERFORT, a buttress built behind a scarp wall for the purpose of strengthening the latter.

COUNTERGUARD, large outwerworks, open at the gorge, designed to protect the faces of bastions and ravelins.

COUNTERMlNE, a tunnel excavated beneath the glacis through the counterscarp wall, terminating in a small shallow pit designed to house an explosive charge which was fired by the defenders when the enemy occupied by the ground directly above the mine.

COUNTERMURE, a wall raised behind another to take its place when a breach is made; a form of retrenchment. COUNTERSCARP, contrascarpa - i., the outer wall of the ditch facing the ramparts.

COUNTERSCARP GALLERY, a casemate within the counterscarp fitted with musketry loopholes to defend the ditch and scarp wall.

COUPURE, a cut in the parapet and walkway of a rampart designed to prevent an enemy from turning the salient of the work.

COUVRE PORTE, a work designed to cover approaches to the main fortress.

COVERED WAY, COVERTWAY, chemin couvert - f., strada coperta - i., a path on top of the counterscarp, protected by a parapet formed from the crest of the glacis.

CRENELLATION, the gap in a parapet; an embrasure.

CROCHET, a narrow passage between the head of a traverse and the parapet of the covertway to allow for movement of troops along tha latter

CROWNWORK, opera coronata - i., a powerful outerwork, projecting ahead of the main enceinte to cover a vulnerable area, consisting of a central bastion supported by two demi-bastions.

CROWNED-HORNWORK, opera coronata - i., a horn work protected further by a crownwork.

CURTAIN, cortina - i., the main wall of a defensive work, usually the length of a rampart between two bastions.

CUTTING, a narrow opening in the parapet of the covered way, cut through the crest of the glacis, to allow for the passage of troops onto the glacis designed to facilitate counterattacks and are therefore usually found on the parapets of places-of-arms.

DEAD GROUND, an area of ground in the vicinity of a fortified work not covered by the defenders’ guns and thus creating a vulnerable spot in the defences.

DEMI-BASTION, a half-bastion with one face and one or two flanks.

DEMI-CAPONIER, a caponier having only one protected flank.

DEMI-LUNE, mezzaluna - i., a small detached outerwork, similar to a ravelin but smaller, placed before a curtain.

 DETACHED LUNETTE, an advanced work in the form of a lunette connected to the covered way by a caponier.

DISCHARGING ARCH, an arch built to relìeve the weìght of the wall above a weak area.

DITCH, fossa - i., fossé - f., a dry trench outside a fortified work, usually rock-hewn, to obstruct direct assault on the main walls.

DONJON, the keep or strongest part of a castle.

DRAWBRIDGE, a bridge spanning a moat or a ditch, hinged and provided with a raising and lowering mechanism so as to hinder or enable passage into a castle or a fortress.

DRUM, one of the cylinders of stone which form a column, sometimes used in the walls of a fortress, especially if the latter was built in the vicinity of the ruins of a classical site, from where such material was eagerly quarried as building material.

EGLISE-DONJON, a church-keep or fortified chapel.

EMBRASURE, an opening cut in the parapet through which a gun could be fired withour exposing the guncrew, normally wider at the front than at the rear; in casemates an enlargement of a window opening by means of splayed sides.

ENFILADING FIRE, fire from the flank of a bastion along the faces of the adjacent works.

ENCEINTE, the fortified perimeter of a densive work, and the area enclosed by it.

ENTRENCHMENT, trincieramento - i., an inner, second line of defence sometimes accompanied by a trench; coastal entrenchment, a entrenchment built along the shoreline to impede an enemy disembarkation.

ENTRENCHED BASTION, a large bastion with an entrenchment built into its gorge.

ESCARPE, scarp, the wall of a fortified work which forms the side of the ditch facing outwards towards the counterscarp.

ESCARPMENT, a steep slope in front of a fortification to impede an enemy’s approach.

ESCUTCHEON, a shield, usually of stone or marble, fixed to a fortress wall or above a gateway on which are depicted coats-of-arms and other heraldic insignias.

ESPLANADE, an open, levelled space between a citadel and the buildings of a town, to ensure a clear view of the immediate approaches to the fortress.

FACE WALL, the front, exposed retainíng wall of a bastion or other defensive work; the wall of a bastion between the salient angle and the shoulder of a flank.

FAUSSE-BRAYE, falsa braga - i., an outer rampart, or vans mur, added to the walls of a fortress, but lower in height than the main walls and preceded by a ditch. The proteichisma of Greek and Byzantine fortifications.

FLAT-ARCH, an arch with a horizontal intrados, having little or no convexity.

FLANK, that section of a fortified work designed to defend an adjoining work and to provide enfilading fire.

FLEUR-DE-LYS, French royal lily, conventionalized as an ornament and frequently found decorating the roof of   echaugettes.

FRONT OF FORTIFICATION, the distance between the salient points of two adjacent bastions.

FOOT OF GLACIS, the line were the sloping glacis meets the level ground of open country.

FOUGASSE, a rock-hewn mortar.

FURROW OF GLACIS, the line where two stretches of glacis meet together at the re-entrant angle of the place-of-arms and covertwav.

FORT, a fortified military establishment, a fortress without a city.

FORTRESS, a fortified city or other major defensive work.

FLECHE, a arrow shaped work, similar to a redan; a lunette attached to the main works by a long caponier.

GABION, a cylindrical earth-filled wicker basket used as a temporary parapet to shield both guns and men in filed positions or in makeshift countermures.

GATE, MAIN, Porta Reale - i., the principal entrance into a fortress, protected by a drawbridge and a ditch, internally containing one or more guardrooms which may be fitted with loopholes to cover the approaches to the doorway; the exterior facade usually of neoclassical design, embellished, especially in the 17C and 18C, with Baroque and Rococo decorations.

GATE COURT, the courtyard between two successive gates of a castle.

GATEHOUSE, a building accompanying a gateway of a castle or a fortress.

GATE-TOWER, a tower, sometimes two tower joined together, containing the gate of a fortress or castle and usually housing the mechanism for the drawbridge.

GLACIS, spalto - i., the sloping ground in front of a fortress spanning from the top of the parapet of the covertway down until it reaches the open country, cleared of all obstacles to bring an advancing enemy into the direct line of fire.

GIBBS SURROUND, the surround of a doorway consisting of alternating large and small blocks of stone.

GORGE, the interior side, or neck, of a bastion, outerwork or other defensive work not protected by a parapet.

GUN-LOOP, GUN-PORT, a circular loophole with accompanying vision-slit through which early medieval guns and cannon could be fired from behind a parapet or from within a casemate.

GUN-TOWER, a hollow or casemated tower fitted with embrasures for cannon.

HOARD, HOARDING, a covered wooden gallery projecting from the top or a wall or parapet of a castle to enable the defenders to shower missiles on attackers at the foot of the wall.

HORNWORK, opera a corna - i., an outerwork consisting of a front of two demi-bastions joined by a short curtain wall.

KASR, an Islamic castle in North Africa.

KEEP, the last defensible stronghold of a fortress or castle.

LINE OF DEFENCE, the line of fire from the flank of a bastion along the face of the adjacent bastion.

LINTEL, a horizontal stone placed over an opening to carry the weight of the wall above it.

LODGEMENT, a temporary defensive work erected by the enemy on a captured section of a besieged fortress.

LOOPHOLE, a long and narrow opening in a wall to provide for vîsion and small arms fire; loop window or arrow slit, a loophole for crossbows; gun loop, a loophole for small early cannon;

LUNETTE, a large outerwork in the shape of a detached bastion; similar to a ravelin.

MAGAZINE, gunpowder magazine, polverista, a storage place for gunpowder and other munitions.

MAGISTRAL LINE, the highest point of the scarp of a rampart or any other fortification which, when shown on a plan, is drawn thicker than the other lines.

MAIDEN TOWER, the keep, donjon or principal tower of a castle.

MARBLE THROUGH-COLUMN, antique marble columns used in the building of ramparts to strengthen the walls.

MASONRY, the stonework or brickwork of a building or wall.

MASTIO, a keep or donjon; a stronghold.

MERLON, the solid part of a parapet between two embrasures or crenels.

MEURTRIERES, holes in the ceiling or vault through which offensive materials could be dropped on attackers inside the passage of a gateway; also known as murder holes.

MEZZALUNA, a demi-lune.

MOAT, a wide and deep trench surrounding the walls of a fortress or castle, usually filled with water.

MOTTE, the mound of earth on which the keep or donjon of an Ilth or l2th century castle was built.

MOTTE-AND-BAILEY, an early form of castle which appeared in France and Normandy in the 11C and 12C, consisting of a motte, a mound of earth on which stood a tall wooden tower overlooking the bailey, a larger palisaded courtyard.

MUD BRICK FORTS, fortified works built of any type of sun-dried clay brick.

MURUS, a defensive wall of stone or brick built around a Roman town.

MUSHRABIYA, in Moslem fortifications, a machicolated balcony, sometimes with embattled parapet, projecting over a gate or entrance.

NECK OF BASTION, the gorge of the bastion.

OPENWORK, any work not protected by a parapet at the gorge.

OUTWORK, OUTERWORK, a defensive structure placed outside the main enceinte of a fortified work.

PALISADE, a series of wooden poles with pointed times, sometimes fortified with iron tips (punte di ferro), driven into the earth and used as a fence or fortification; wooden palisaded gates were placed in front of the drawbridges leading into the main gateways.

PARAPET, parapetto - i., a breastwork on top of a rampart intended to provide shelter for troops behind it.

PAS-DE-SOURIS, a staircase giving access from the ditch to the covertway and places-of-arms.

OPERE DA SOLDATO, also Arcbitettura Soldatesca - i., earthworks and other field fortifications erected by the troops themselves, such as redoubts, palisades, breastworks and trenches.

ORILLION, oreccbino, guardanaso - i., a projecting shoulder of a bastion designed to cover the flank.

PIAZZA, a large open space or courtyard inside a fortress, a parade ground.

PIAZZA BASSA, a low platform in the flank of a bastion; a casemated battery in the flank of a bastion.

PLINTH, a square or rectangular base so designed to give the appearance of a platform.

POLVERISTA, a specially built magazine used for the storage of gunpowder.

POMERIO, the open areas between the walls of a fortress and the urban fabric, to allow space for troops to assemble.

PORTCULLIS, a large iron or wooden grating, used to block a passage when released vertically in retaining grooves cut in the jabs of a fortified gateway.

POSTERN, a sally port; a vaulted stone tunnel under the ramparts leading to an inconspicuous rear gate used for sorties in war; a small door near a larger one.

QUOIN, a hard stone used to reinforce an external corner or edge of wall.

RAMPART, a thick wall of earth or masonry forming the main defence of a fortress, usually reinforced from the rear with terreplein.

RAVELIN, a triangular outerwork placed in front of a curtain to defend it.

REDAN TRACE, a fortification consisting redans forming a serrated system of of a series of

REDOUBT, ridotto - i., a small fortified work designed as an infantry stronghold; sometimes built inside a bastion or ravelin as a retrenchment, or in the field as a defence against cavalry attack; coastal redoubt, an infantry stronghold placed on the shoreline against a sea-borne invasion.

REVETMENT, a retaining wall of a fortress.

RUBBLE WALL, a wall of uncoursed stones of irregular shapes and sizes.

SALLY PORT, porta falsa - i., a concealed gate or underground passage leading from inside the fortress into the ditch; a postern.

SALIENT OF BASTION, corner of a bastion.

SALlENT OF BASTlON, the projecting front angle of a bastion.

SHELL-KEEP, a stone keep with an internal courtyard and dwellings placed against its inner side. Late to develop into the inner ward of a castle.

SHOULDER OF BASTION, the angle between the face and the flank of a bastion.

SPUR, an arrow-shaped work; spur of a bastion, sharp-edged buttress placed at foot of a rounded salient of bastion. TALUS, an outward sloping wall, commonly used in medieval defences.

TENAILLON, an outerwork designed to protect a ravelin.

TERRA, term used in medìeval tìmes to denote a walled town or city.

TERRAPLEIN, the packing of earth forming the body of a rampart; the gently sloping ground behind a parapet, formed from packed earth.

TRACE, the perimeter or ground plan of a fortified work.

TRAVERSE, a defensive barrier, consisting of a parapet or simple wall placed at rìght-angles to the main line of defence and in order to protect the defenders from flanking fire; commonly found on covertways (18C) but also on the main ramparts themselves.

TENAILLE, tenaglia - i., a small outerwork placed inside the ditch, between two adjoining bastions, and designed to protect the curtain wall; usually detached but sometimes linked to the flanks or shoulders of adjoining bastions.

TROPHIES, in baroque fortifications, carved or sculptured features representing the trophies of war - cannon, shields, flags etc., used for decorative purposes.

TURRET, a small and slender tower, sometimes projecting from the main rampart. 

VOUSSOIR, wedge-shaped stones used in an arch or vault. 

VENTILATION SHAFT, openings in the ceilings of casemates used as cannon or musketry galleries which are designed to channel the escape of toxic fumes generated by burnt gunpowder.

WALL-TOWER, a tower built as part of a rampart of a castle, usually projecting outwards from the main curtain wall.

WARD, an outerwork of a castle.

WATCH-TOWER, a small tower, lightly fortified and used as a lookout post.

WICKET, a small door forming part of a larger one.

WING, a long and narrow rampart protecting the exposed sides of a horned or crowned work.