Château de Sedan

A Benedictine priory of the abbey of Mouzon, Saint-Martin, stood on the rock above the Meuse before any castle did; it is recorded in 1306, and excavation indicates its church had been founded in the eleventh century. Évrard II de La Marck-Arenberg took possession of the site in 1424 through his brother-in-law Louis de Braquemont, bringing him the dowry that Guillaume de Braquemont had never provided. He held a stretch of the right bank of the Meuse from Sedan to Maastricht, and backed Charles VII against the English.

Over six years from about 1424 he raised a roughly triangular castle around the church, which became its chapel: twin entrance towers screened by a châtelet, a rectangular keep already part of the priory, and a round western tower later enlarged into the Grosse Tour. The plan can look archaic for its date, taking little account of an attacker's artillery. When Évrard died in 1440 his son Jean de La Marck reinforced the fortress and doubled its area.

Archduke Maximilian's siege of the place failed in 1495, as did Charles V's in 1521. Robert II de La Marck, Jean's grandson, carried out the heaviest work: the circular boulevard of 1530, a princely lodging of a hundred metres along the town-side rampart begun the same year, and the governor's lodging in 1536. Around 1550 earth filling between the ramparts and a new wall taken from the lower court created the cannon terraces, thickening the curtains from 4.5 metres to 26 and enclosing eighteen small quarters for the troops within the mass.

Two triangular bastions were begun on the north-east front in 1553, the Gouverneur finished in 1557 and the Fourchu in 1559; the bastions des Dames and du Roy were delivered in 1572. By the middle of the century the castle covered 10,000 square metres. Henri II granted the lords of La Marck the title of sovereign princes. The last campaign on the defences had Marin Fourre as its first designer, then Marc-Aurèle Pazin of Ferrara from 1577 and Jean Errard of Bar-le-Duc after 1585. In 1606 the place was besieged by Henri IV and had to surrender.

Marshal Turenne was born in the castle in 1611. The principality was absorbed into France after the battle of la Marfée in 1641 and the failure of Cinq-Mars's conspiracy against Richelieu in 1642: the last prince, Frédéric-Maurice de La Tour d'Auvergne, was compelled to hand the castle to Louis XIII, who imprisoned him, and to give up the principality by treaty in September 1642.

Marshal Fabert was the first governor of Sedan for the King of France, and in 1650 built the Fabert warehouses, six-storey stores for grain. The castle was turned into a garrison, and in 1699 Vauban built the porte des Princes, adapted to the progress of artillery and the only intervention here by that architect. The fortress then occupied 35,000 square metres over seven levels.

Napoleon Bonaparte visited in 1803 and had the Sedan princes' collection of armour transferred to Paris, where some pieces are displayed in the Musée de l'Armée. The church of Saint-Martin was demolished in 1822 to install a cannonball park.

On 1 September 1870, encircled by the Prussian and Saxon armies, the Army of Châlons was defeated at the battle of Sedan. Napoleon III had the white flag raised over the fortress, and the act of capitulation was signed at the château de Bellevue between Frénois and Glaire. Following the battle the stronghold was declassified and its bastion network destroyed: some of the hornworks in front of the bastions were dynamited before the century was out, and dynamite trials on the bastion du Gouverneur and the bastion Fourchu in 1873 left both largely gutted.

From January 1917 to November 1918 the citadel served as an internment camp for thousands of French and Belgian civilian resisters, condemned to forced labour by the German authorities. It was known locally as le Bagne. The number of dead is uncertain, but it very likely exceeded a thousand and was probably appreciably higher.

The French army ceded the castle to the town in 1962, and several restoration campaigns followed; the château-haut and its four bastions were classified as a historic monument by decree of 4 January 1965. The castle holds the municipal museum, one room of it given to the war of 1870, with a hotel in the Fabert warehouses and a restaurant within the walls. Sometimes called the largest fortress of medieval origin in Europe, it drew 145,300 visitors in 2024 and was voted « Monument préféré des Français » on 13 September 2023.