The urban fortifications

A project initiated by Vauban

Reinvigorated by the English invasion of 1761

Facing the coast of southern Brittany and the mouth of the Loire, Belle-Ile has been a fiercely fought over strategic position for centuries. Its agriculture and freshwater resources made it an ideal base of operations for any navy, as demonstrated by the construction of the citadel in the 16th and 17th centuries and its further remodelling by Vauban.
Vauban had also planned for a ring of intricate fortifications along Le Palais’ heights, designed to support the citadel’s flank . Lack of funding cut the scope of the work to the zones immediately around the citadel.
The invasion of 1761 exposed this weakness clearly when English guns, positioned precisely where a Vauban had planned a bastion, breached the walls of the citadel following weeks of bombardment. Upon the island’s return 2 years later, it was decided to complete the urban ring so as to guarantee Belle-Ile’s security

A testament to the First and Second Empires

Inscribed to the supplementary inventory of historical monuments

Work began in 1802, with Napoléon Bonaparte’s rise and the establishment of the First French Empire. Construction was originally carried out by French army sappers, but this proved too costly and penal-colony convicts were brought in to replace them. 1815 and the ensuing collapse of the Empire halted progress entirely and from 1820 onwards, a number of proposals were considered for the completion of the defences. Finally, work restarted under the Second Empire before being completed in 1877, shortly after Napoléon III’s downfall.

Nearly obsolete at its completion, Palais’ defensive ring was never tested by fire: advances in modern artillery had comprehensively changed how war was fought and Belle Ile had since lost some strategic importance. It stands today as a uniquely intact example of 18th and 19th century military architecture, and as such has been inscribed to the Supplementary Inventory of Historic Monuments.