The Citadel of Montreuil-sur-Mer, France

The citadel of Montreuil is built on a 50 meter rise which dominates the Canche valley. With its natural defence provided by the Canche marshes to the north and the dry valley of the Madelaine to the west, it is joined to the town in the south east. Construction of the citadel began in 1567. It is a complex structure which was die result of seven different campaigns of construction. It succeeds the early XIIIth century royal castle, of which some elements remain. Built straddling the limits of the town, it has two distinct fronts of attack, one facing the town and the other facing open country. Altered several times up to the end of the XIXth century the citadel was de-militarised in 1929, three years after being classified as a Historical Monument.

The gate
The principal entrance to the citadel faces the town. The engineers have placed an accumulation of obstacles in front of this vulnerable point. The gate is framed by two half-bastions. Under Vauban, this system was complemented by a demi-lune, an advanced triangular shaped fortification work which protects the two curtains between the two bastions. The gate is composed of two separate openings, a carriage gateway and a postern gate which is now walled up, an arrangement which is a vestige of the Middle Ages. Access to the citadel was defended by a cantilever draw-bridge, which was replaced by an earth embankment in 1894. The gate retains the embrasures through which the cantilever arms, wooden beams connected to the drawbridge by chains, operated. Inside, the archway and the walls still bear the traces of the vertical channels within which a portcullis operated. The whole is completed by a guard-house which was added in the XVIIIth century.

The Castle of Philippe Auguste
After the entry of the town into the royal domain in 987 on the accession of Hugues Capet, a royal castle was built. It is first mentioned with certainty in 1042.
Until 1204, Montreuil was die only royal possession in the north of France. This strategic position very quickly placed the town at the heart of a conflict between the Capetians and the English Plantagenets, allied to the Counts of Flanders, of Boulogne and Ponthieu. This threat persuaded Philippe Auguste to build a new royal castle which is in part preserved within the 1567 citadel.

Two massive towers bracket the broken arch entrance. This polygonal castle, in the image of the slightly later one at Boulogne-sur-Mer, was separated from the town by a ditch. At each of its angles there was a salient, multi-level, round tower, with radiating archery slits. Originally built exclusively in sandstone, the various defensive changes of the XVIth century have necessitated the reconstruction of the upper parts in brick.

Queen Berthe's tower
This gate tower which is equipped with many systems of defence, has served as access to the town of Montreuil-sur-Mer for a long period. It was called the castle gate because of its proximity to Philippe Auguste's castle. Built in the middle of the XIVth. century its volume and the thickness of its walls are the solution provided by its architects to the evolution in the means of attack and especially the significant development of the cannon. During the construction of the citadel, this gate which gives access directly to the interior of the fortress, was judged to be dangerous and was closed as early as 1599. It preserves the memory of Berthe of Holland, wife of Philippe 1st, the King of France, who was repudiated in 1091 and who died at Montreuil in 1094. Legend has it that she was locked up in this tower.

Tower E
In the XVth Century, progress in artillery forced military engineers to imagine makeshift solutions. The technique developed was the raising of masses of earth behind walls in order to make them more resistant to cannon fire. The height of the curtains and of the towers was reduced to present a smaller target for the enemy's projectiles. The towers were filled with earth to provide solid emplacements for artillery pieces. Tower E illustrates this architectural evolution. Originally completely in sandstone and taller, it was refaced in brick at the end of the XVth century.

The bastions of the citadel
Italian engineers provided a final response to the problem of artillery by inventing the bastion. The circular hollow towers were replaced by vast pentagonal fortification works filled with earth on which multiple cannons were sited. These bastions axe separated by curtains which they protect with their fire. Their angular de¬sign permits the resolution of the problem of dead ground. From this time on the enemy was exposed to the defender's fire, whatever their position.

In the XVIth. Century, the proximity of the frontier of the Spanish low-countries, a dozen kilometers from Montreuil, induced King Charles IX (1559-1574) to improve the defences of the town. In 1567, he built a citadel with five bastions. Its design in the shape of a star, represented the latest innovations in terms of defence. The safety exit, built at the extremity of the bastion as an extension of the castle gate, provides an exit to the country in case of an attack on the town.

As in all the citadels built at the same time, the body of the fortress is enclosed by advanced defensive works designed to slow the progress of the attacker and to delay the crossing of the ditch. On the outside edge of the ditch, the covered way houses defenders armed with muskets protecting the glacis, vast areas of slightly sloped terrain arranged around the fortress.


The White Tower
It is the colour of the chalk that gives its name to the White Tower. This tower was part of the town before being absorbed into the citadel. Rebuilt around 1500, it has kept its XIIIth century sandstone base with its archery slits. The ground floor, with its ogival roof vaults illustrates the adaptation of the new techniques of defence. The archery slits have here given way to cannon ports, circular openings surmounted by observation slits. On the second floor, the guard-house topped, by a pepper-pot roof, has given in to the desire for comfort and has several windows and a fireplace.

The rampart-walk
Its construction in the XVIth. century required the lowering of the towers of the royal castle. It is supported by a series of massive brick arches. Without any real defensive advantage in modern times, it facilitates movement along the northern front of attack. Its commanding position over the surroundings allowed warnings of attack to be given. From the rampart-walk can be seen from the east to the west, the lighthouse at le Touquet, the sea-side towns, the wind farm at Widehem, la Canche, the Carthusian monastery of Notre-Dame des Pres at Neuville-sous-Montreuil and the forest of Hesdin.

The casemates
Integrated into the bastion, the casemates are made up of five chambers arranged in line, covered by cradle vaulted ceilings. Each chamber was built or two levels separated by a moveable floor, which is today no longer present. The firing slits are surmounted by an opening which permitted the evacuation of the gun-smoke They ensured the defence of the ditch nearest to the fortification.

Their construction was ordered in 1844 by Louis Philippe 1st who feared an attack on France by Prussia. During the first world war they housed the communications centre of the British General Headquarters in Europe.

The arsenal
The citadel of Montreuil is equipped with an arsenal, a building housing arms and military equipment. Built in the reign of Louis XIV, it originally had two floors.

The chapel
The chapel dates from 1764. This rectangular building has a neo-classical facade.

The powder magazine
Constructed around 1670, the powder magazine is built on the lines of those of Vauban in the Alps, particularly that at Mount Dauphin.

It is surrounded by an isolation wall, through which there is an entrance defended by a sentry-box. The building is braced by nine massive buttresses with a passage between them and the building. The roof vault is very high and is covered with earth so that projectiles will bury themselves without exploding. The floor was raised in order to avoid rising damp.

GLOSSARY
Dead ground : Terrain not reachable by defensive fire from a fortification.
Bastion : A five sided, masonry covered, earth-work fortification.
Curtain : A wall of fortification between two towers ot two bastions.
Demi-lune : A low, triangular work of fortification placed in front of a curtain and between two bastions.

Service d'Animation du Patrimoine et des Musees de la ville de Montreuil-sur-Mer, taken from leaflet circa 2004.