Initial Vauban project 1683 (≈ 1683)
First proposal for a bastioned enclosure for Le Palais.
1761
Seat revealing weaknesses
Seat revealing weaknesses 1761 (≈ 1761)
Taking dreads leading to the fall of the citadel.
1802
Marescot project
Marescot project 1802 (≈ 1802)
Camp cut off with proposed strong detachments.
1807-1812
Construction of imperial glasses
Construction of imperial glasses 1807-1812 (≈ 1810)
Buildings A, B, C and Bangor Gate.
1840-1870
Completion of the enclosure
Completion of the enclosure 1840-1870 (≈ 1855)
Courtines and Beausoleil works built.
1860
Final pattern adopted
Final pattern adopted 1860 (≈ 1860)
Laying of existing glasses.
2004
Historical Monument
Historical Monument 2004 (≈ 2004)
Recognition of the fortified heritage.
Aujourd'hui
Aujourd'hui
Aujourd'hui Aujourd'hui (≈ 2025)
Position de référence.
Key figures
Sébastien Le Prestre de Vauban - Military engineer
Author of the first precinct project in 1683.
Marescot - Inspector General of Engineering
Proposes a camp cut off in 1802.
Origin and history
The urban enclosure of the Palais, built mainly between 1807 and 1870, is a bastioned fortification of nearly one kilometre, designed to protect the citadel of Belle-Île-en-Mer. It consists of four bastioned fronts (18-19, 19-20, 20-21, 21-22), a ditch, a crenellated gallery, a covered road with reduced, and a glacis. Three bastions (19, 20, 21) replaced old dreaded ones of 1761, while a hornwork (Beausoleil) closed the enclosure north side. The doors (Bangor, Vauban, Locmaria) and poternes connect the interior to the outside, supplemented by powder shops and case-based barracks.
The initial project dates back to 1683, when Vauban proposed a enclosure to secure the heights overlooking the citadel, a weakness revealed during the siege of 1761. Under the Consulate and the Empire, work began in 1803 with stunned glasses and cut-outs (A, B, C), but the cut-off camp remained unfinished in 1815. From the 1840s, the enclosure was finally built in masonry, integrating existing works and adding Beausoleil's work. Classified as a Historical Monument in 2004, it illustrates the evolution of fortifications from the 17th to the 19th century, despite a theoretical obsolescence against modern artillery.
The enclosure preserves traces of successive military adaptations: platforms for cannons (138 mm, 120 mm, 22 cm mortars), powder shops, and ice plantations inherited from the 19th century. Although designed to withstand the sieges, its usefulness declined with technological progress, but it remained armed until the end of the 19th century. Its ranking recognizes the rarity of a fortified ensemble combining elements of Vauban, the First Empire, and Second Empire developments, bearing witness to three centuries of military history.
The projects multiplied between 1819 and 1860 before the adoption of a definitive route in 1860, putting on masonry glasses and connecting them with courtines. The Bangor Gate (1811) and the reduced A, B, C are preserved, while the courtine 18, built in the 1840s, strengthens the connection with the sea. Diplomatic tensions of the 1840s accelerated the work, completed between 1861 and 1870. The enclosure, although theoretically exceeded by the striped artillery, remains operational in the island context, where the deployment of heavy seat guns is complex.
Vauban, in his 1683 report, stressed the need to control the south and west heights to prevent an effective siege of the citadel. The siege of 1761 confirmed this vulnerability, when the taking of dreads led to the fall of the square. The six dreads of 1761, partially reinforced during the revolutionary wars, are integrated into the 19th century. The military genius, under the direction of Marescot in 1802, first proposed a cut-off camp with strong detachments, before returning to the idea of a continuous enclosure, closer to the initial plans of Vauban.