A caponier is a type of defensive structure in a

fortification A fortification (also called a fort, fortress, fastness, or stronghold) is a military construction designed for the defense of territories in warfare, and is used to establish rule in a region during peacetime. The term is derived from Lati ...

. Fire from this point could cover the ditch beyond the curtain wall to deter any attempt to storm the wall. The word originates from the French ', meaning "chicken coop" (a ''

capon A capon (from , genitive ''cāpōnis'') is a male chicken that has been castrated or neutered, either physically or chemically, to improve the quality of its flesh for food, and, in some countries like Spain, fattened by forced feeding. Histor ...

'' is a castrated male chicken). In some types of

bastion A bastion is a structure projecting outward from the curtain wall of a fortification, most commonly angular in shape and positioned at the corners of the fort. The fully developed bastion consists of two faces and two flanks, with fire from the ...

ed fortifications, the caponier served as a means of access to the

outworks An outwork is a minor fortification built or established outside the principal fortification limits, detached or semidetached. Outworks such as ravelins, lunettes (demilunes), flèches and caponiers to shield bastions and fortification curtains ...

, protecting troops from direct fire; they were often roofless. Although they could be used for firing along the ditch, the flanks of the bastions were the main defence of the ditch by fire. In later

polygonal fort A polygonal fort is a type of fortification originating in France in the late 18th century and fully developed in Germany in the first half of the 19th century. Unlike earlier forts, polygonal forts had no bastions, which had proved to be vulnerab ...

s, caponiers were often roofed and were not intended as a type of ''

covered way In military architecture, a covertway or covered way (, ) is a path on top of the counterscarp of a fortification. It is protected by an embankment which is made up by the crest of the glacis. It is able to give the fort's garrison a position ...

'', but as the main way of keeping the ditch clear of a besieger.

History

Originally the term referred to a covered passageway that traversed the

ditch A ditch is a small to moderate trench created to channel water. A ditch can be used for drainage, to drain water from low-lying areas, alongside roadways or fields, or to channel water from a more distant source for plant irrigation. Ditches ...

outside the curtain of a

fortress A fortification (also called a fort, fortress, fastness, or stronghold) is a military construction designed for the defense of territories in warfare, and is used to establish rule in a region during peacetime. The term is derived from L ...

. Fire from this point could cover the ditch beyond the curtain wall to deter any attempt to storm the wall. Thus the passageway was equipped with musket ports and

cannon A cannon is a large-caliber gun classified as a type of artillery, which usually launches a projectile using explosive chemical propellant. Gunpowder ("black powder") was the primary propellant before the invention of smokeless powder during th ...

ports that fired along the ditch. While fortifications were evolving to the simpler

polygonal In geometry, a polygon () is a plane (mathematics), plane Shape, figure made up of line segments connected to form a closed polygonal chain. The segments of a closed polygonal chain are called its ''edge (geometry), edges'' or ''sides''. The p ...

style, the term was sometimes used to describe the flanking positions set at the corners of the ditch that provide the same function in that style of fort, especially in France. In bastioned forts, it usually takes the form of a low open passage, often partly sunken into the floor of the ditch and projecting outward into and across it, with access from the main fortress via a passage through the curtain wall. The roof, if any, was often made against weather, observation and small arms fire, not artillery. As polygonal fortresses evolved, caponiers became more substantial, higher and protected above from plunging fire with masonry and earth cover. In late 19th century, works which were largely underground, caponiers were reached via a tunnel from within the fort.

Equipment

The caponier is usually equipped with a

firing step Firing may refer to: * Dismissal (employment), sudden loss of employment by termination * Firemaking, the act of starting a fire * Burning; see combustion * Shooting, specifically the discharge of firearms * Execution by firing squad, a method of ...

and

rifle A rifle is a long gun, long-barreled firearm designed for accurate shooting and higher stopping power, with a gun barrel, barrel that has a helical or spiralling pattern of grooves (rifling) cut into the bore wall. In keeping with their focus o ...

ports to allow troops to fire along the ditch, and often has provision for small cannon to sweep the ditch as well. To clear the smoke and fumes from the firing the roof of the caponier is often provided with ventilation ports. To avoid fire from one caponier bearing on the next, caponiers are sometimes set at alternate corners of the fort, so that they fire towards a blank wall at the opposite end of the ditch, giving full coverage of the ditch without subjecting the next caponier to fire. The length of the straight sections of the ditch is chosen so that it can be covered by fire from a single caponier. Caponiers are often wedge shaped so that they can fire down both angles of the ditch.

Counterscarp battery

An alternative to the caponier is a

counterscarp A scarp and a counterscarp are the inner and outer sides, respectively, of a ditch or moat used in fortifications. Attackers (if they have not bridged the ditch) must descend the counterscarp and ascend the scarp. In permanent fortifications, the ...

battery, dug into the outer face of the corner of the ditch, giving a similar

field of fire The field of fire or zone of fire (ZF) of a weapon, or group of weapons, is the area around it that can easily and effectively be reached by projectiles from a given position. Field of fire The term originally came from the ''field of fire'' in f ...

. Reached by a tunnel from within the fort, it does not have the vulnerable roof that the caponier has, but being outside the ditch, is potentially more vulnerable to

mining Mining is the Resource extraction, extraction of valuable geological materials and minerals from the surface of the Earth. Mining is required to obtain most materials that cannot be grown through agriculture, agricultural processes, or feasib ...

. Both structures may be found in the same fort.

Locations of caponiers

Caponiers are a common feature of 18th- and 19th-century fortifications and are found on almost all the

Victorian Victorian or Victorians may refer to: 19th century * Victorian era, British history during Queen Victoria's 19th-century reign ** Victorian architecture ** Victorian house ** Victorian decorative arts ** Victorian fashion ** Victorian literatur ...

forts of Malta, the

Palmerston Forts The Palmerston Forts are a group of forts and associated structures around the coasts of the United Kingdom and Ireland. The forts were built during the Victorian period on the recommendations of the 1860 Royal Commission on the Defence of the ...

in Britain, the Lisbon Entrenched Camp forts in

Portugal Portugal, officially the Portuguese Republic, is a country on the Iberian Peninsula in Southwestern Europe. Featuring Cabo da Roca, the westernmost point in continental Europe, Portugal borders Spain to its north and east, with which it share ...

, fortifications in many

Nordic countries The Nordic countries (also known as the Nordics or ''Norden''; ) are a geographical and cultural region in Northern Europe, as well as the Arctic Ocean, Arctic and Atlantic Ocean, North Atlantic oceans. It includes the sovereign states of Denm ...

. Caponiers were also found in *

Birgu Birgu ( , ), also known by its title Città Vittoriosa ('Victorious City'), is an old Fortifications of Birgu, fortified city on the south side of the Grand Harbour in the Port Region, Malta, Port Region of Malta. The city occupies a promontory ...

main ditch *

Fort Manoel Fort Manoel ( or ''Fortizza Manoel'') is a star fort on Manoel Island in Gżira, Malta. It was built in the 18th century by the Order of Saint John, during the reign of Grand Master António Manoel de Vilhena, after whom it is named. Fort Ma ...

Fort Ricasoli Fort Ricasoli () is a bastioned fort in Kalkara, Malta, which was built by the Order of Saint John between 1670 and 1698. The fort occupies a promontory known as Gallows' Point and the north shore of Rinella Bay, commanding the entrance to the G ...

Boden Fortress Boden Fortress () is a modern fortress consisting of several major and minor forts and fortifications surrounding the city of Boden, Norrbotten, in northern Sweden. The fortress was originally intended to stop or delay attacks from the east or co ...

in Sweden * Brest-Litovsk fortress, * Camden Fort Meagher, Crosshaven, Cork Harbour, Ireland *

Coalhouse Fort Coalhouse Fort is an artillery fort in the eastern English county of Essex. It was built in the 1860s to guard the lower Thames from seaborne attack. It stands at Coalhouse Point on the north bank of the river, at a location near East Tilbury ...

Essex Essex ( ) is a Ceremonial counties of England, ceremonial county in the East of England, and one of the home counties. It is bordered by Cambridgeshire and Suffolk to the north, the North Sea to the east, Kent across the Thames Estuary to the ...

, England *

Craignethan Castle Craignethan Castle is a ruined castle in South Lanarkshire, Scotland. It is located above the River Nethan, a tributary of the River Clyde, at . The castle is two miles west of the village of Crossford, and 4.5 miles north-west of Lanark. Built ...

Scotland Scotland is a Countries of the United Kingdom, country that is part of the United Kingdom. It contains nearly one-third of the United Kingdom's land area, consisting of the northern part of the island of Great Britain and more than 790 adjac ...

contains a good 16th century example. *

Eluanbi Lighthouse Eluanbi Lighthouse is a lighthouse located on Cape Eluanbi, the southernmost point of the main island of Taiwan, which separates Taiwan's South Bay from Banana Bay and the Taiwan Strait and the South China Sea from the Philippine Sea. It is ...

in southern

Taiwan Taiwan, officially the Republic of China (ROC), is a country in East Asia. The main geography of Taiwan, island of Taiwan, also known as ''Formosa'', lies between the East China Sea, East and South China Seas in the northwestern Pacific Ocea ...

Fort Glanville Conservation Park Fort Glanville Conservation Park is a protected area located in the Australian state of South Australia located in Semaphore Park, South Australia, Semaphore Park, a seaside suburb of Adelaide consisting of a functional 19th century fort listed ...

Adelaide Adelaide ( , ; ) is the list of Australian capital cities, capital and most populous city of South Australia, as well as the list of cities in Australia by population, fifth-most populous city in Australia. The name "Adelaide" may refer to ei ...

South Australia South Australia (commonly abbreviated as SA) is a States and territories of Australia, state in the southern central part of Australia. With a total land area of , it is the fourth-largest of Australia's states and territories by area, which in ...

Fort Hamilton Fort Hamilton is a United States Army installation in the southwestern corner of the New York City borough of Brooklyn, surrounded by the communities of Bay Ridge and Dyker Heights. It is one of several posts that are part of the region which ...

New York City New York, often called New York City (NYC), is the most populous city in the United States, located at the southern tip of New York State on one of the world's largest natural harbors. The city comprises five boroughs, each coextensive w ...

, USA *

Fort McClary Fort McClary is a former defensive fortification of the United States military located along the southern coast at Kittery Point, Maine at the mouth of the Piscataqua River. It was used throughout the 19th century to protect approaches to the ha ...

, Kittery Point, Maine *

Fort Thüngen Fort Thüngen is a historic fortification in Luxembourg City, in southern Luxembourg. It is sited in Dräi Eechelen Park, in the Kirchberg quarter, in the north-east of the city. It is also colloquially known as Three Acorns (, , ) in refer ...

, Luxembourg * Fort Washington,

Maryland Maryland ( ) is a U.S. state, state in the Mid-Atlantic (United States), Mid-Atlantic region of the United States. It borders the states of Virginia to its south, West Virginia to its west, Pennsylvania to its north, and Delaware to its east ...

, USA *

Fort Wellington Fort Wellington National Historic Site is a historic military fortification located on the north shore of the St. Lawrence River at Prescott, Ontario. The military fortification was used by the British Army, and the Canadian militia for most of t ...

Prescott, Ontario Prescott is a town on the north shore of the Saint Lawrence River in province of Ontario, Canada. The town is a part of the United Counties of Leeds and Grenville. In 2021, it had a population of 4,078. The Ogdensburg–Prescott International ...

, Canada *

Freshwater Redoubt Freshwater Redoubt, also known as Fort Redoubt (map reference ), is an old Palmerston fort built in Freshwater Bay on the western end of the Isle of Wight. Construction work for the fort began in 1855 and was completed in 1856. It was finally so ...

, Isle of Wight, England *

Hurst Castle Hurst Castle is an artillery fort established by Henry VIII on the Hurst Spit in Hampshire, England, between 1541 and 1544. It formed part of the king's Device Forts coastal protection programme against invasion from France and the Holy Roma ...

, Lymington, England * Kyiv fortress *

Petersberg Citadel Petersberg Citadel (German: ''Zitadelle Petersberg'') in Erfurt, central Germany, is one of the largest and best-preserved town fortresses in Europe.Stadtverwaltung Erfurt (17 November 2017) ''Petersberg'' Retrieved 23 December 2017 The citadel w ...

, Erfurt, Germany *

Poznań Fortress Poznań Fortress, known in German as Festung Posen (Polish: ''Twierdza Poznań'') was a set of fortifications in the city of Poznań (German: ''Posen'') in western Poland, built under Kingdom of Prussia, Prussian rule in the 19th and early 20th c ...

Poland Poland, officially the Republic of Poland, is a country in Central Europe. It extends from the Baltic Sea in the north to the Sudetes and Carpathian Mountains in the south, bordered by Lithuania and Russia to the northeast, Belarus and Ukrai ...

Sevastopol Sevastopol ( ), sometimes written Sebastopol, is the largest city in Crimea and a major port on the Black Sea. Due to its strategic location and the navigability of the city's harbours, Sevastopol has been an important port and naval base th ...

(

Ukraine Ukraine is a country in Eastern Europe. It is the List of European countries by area, second-largest country in Europe after Russia, which Russia–Ukraine border, borders it to the east and northeast. Ukraine also borders Belarus to the nor ...

). *

Southsea Castle Southsea Castle, historically also known as Chaderton Castle, South Castle and Portsea Castle, is an artillery fort originally constructed by Henry VIII on Portsea Island, Hampshire, in 1544. It formed part of the King's Device programme to pr ...

Spandau Citadel The Spandau Citadel () is a fortress in Berlin, Germany, one of the best-preserved Renaissance military structures of Europe. Built from 1559–94 atop a medieval fort on an island near the meeting of the Havel and the Spree, it was design ...

* Rhodes medieval town, Greece *

Suomenlinna Suomenlinna (), or Sveaborg (), is a sea fortress composed of eight islands, of which six have been fortified. Located about 4 km southeast of the city center of Helsinki, the capital of Finland, Suomenlinna is a popular destination for bot ...

in Finland *

York Redoubt York Redoubt is a redoubt situated on a bluff overlooking the entrance to Halifax Harbour at Ferguson's Cove, Nova Scotia, Canada, originally constructed in 1793. It was designated a National Historic Site of Canada in 1962. History York Redou ...

and Fort Charlotte,

Halifax Regional Municipality Halifax is the capital and most populous municipality of the Provinces and territories of Canada, Canadian province of Nova Scotia, and the most populous municipality in Atlantic Canada. As of 2024, it is estimated that the population of the H ...

, Canada *

Newhaven Fort Newhaven Fort is a Palmerston fort built in the 19th century to defend the harbour at Newhaven, on the south coast of England. It was the largest defence work ever built in Sussex and is now open as a museum. History Design and construction ...

in East Sussex, UK * East Jiguan Hill Fortress () in Lüshun, Liaoning, China

Gallery

Fort Napoleon003.jpg, Caponier, Fort Napoleon, Ostend, Belgium RavelinAnselm 3.jpg, Caponier between the citadel wall and Ravelin Anselm,

, Germany Malta StLucian three.jpg, Caponier,

Fort San Lucian Fort San Lucian (), also known as Saint Lucian Tower () or Fort Rohan (), is a large bastioned watchtower and polygonal fort in Marsaxlokk, Malta. The original tower was built by the Knights Hospitaller, Order of Saint John between 1610 and 1611 ...

Malta Malta, officially the Republic of Malta, is an island country in Southern Europe located in the Mediterranean Sea, between Sicily and North Africa. It consists of an archipelago south of Italy, east of Tunisia, and north of Libya. The two ...

Malta Tas-Silg three.jpg, Caponier, Fort Tas-Silġ

Malta Tas-Silg six.jpg, Caponier, Fort Tas-Silġ

Caponier, Brest Fortress (Belarus).jpg, Caponier,

Brest Fortress Brest Fortress (; ; ; ), formerly known as Brest-Litovsk Fortress, is a 19th-century fortress in Brest, Belarus. In 1965, the title Hero Fortress was given to the fortress to commemorate the defence of the frontier stronghold during the fi ...

Belarus Belarus, officially the Republic of Belarus, is a landlocked country in Eastern Europe. It is bordered by Russia to the east and northeast, Ukraine to the south, Poland to the west, and Lithuania and Latvia to the northwest. Belarus spans an a ...

Kraków - Wawel - Kaponiera 01.JPG, Caponier.

Wawel The Wawel Royal Castle (; ''Zamek Królewski na Wawelu'') and the Wawel Hill on which it sits constitute the most historically and culturally significant site in Poland. A fortified residency on the Vistula River in Kraków, it was established o ...

Scraesdon Fort - Caponier - geograph.org.uk - 345243.jpg, Caponier, Scraesdon Fort,

Cornwall Cornwall (; or ) is a Ceremonial counties of England, ceremonial county in South West England. It is also one of the Celtic nations and the homeland of the Cornish people. The county is bordered by the Atlantic Ocean to the north and west, ...

United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Northwestern Europe, off the coast of European mainland, the continental mainland. It comprises England, Scotlan ...

Fort Prinz Karl - Saillantkaponniere (2007).jpg, Caponier, near

Großmehring Großmehring is a municipality in the district of Eichstätt in Bavaria in Germany Germany, officially the Federal Republic of Germany, is a country in Central Europe. It lies between the Baltic Sea and the North Sea to the north and the A ...

Germany Germany, officially the Federal Republic of Germany, is a country in Central Europe. It lies between the Baltic Sea and the North Sea to the north and the Alps to the south. Its sixteen States of Germany, constituent states have a total popu ...

References

External links

Amherst Fort - Kent

{{Fortifications Fortification (architectural elements)