Fort de La Prée, built in 1625, is located near the eastern end of the Île de Ré. It was built by Royalist Army after they conquered the are from Huguenots during the Wars of Religion. They used materials salvaged from the remains of the Romanesque abbey of the Châteliers'.
The Duke of Buckingham ignored Fort de La Prée during his three-month siege of Saint-Martin-de-Ré in 1627. This neglect turned out to be a strategic error. Toiras managed to land troops there, and from there force the English to give up their siege and withdraw in defeat.
The fort subsequently underwent modifications under the oversight of several engineers: François Blondel (1664), Louis-Nicolas de Clerville (1672), Le Favolière, and finally Sainte-Colombe (1676). They added the gate, a barracks for 200 soldiers outside the walls, and some other outside works.
In 1685, Vauban, the preeminent engineer of the time, had François Ferr raze parts of the original fort, particularly the keep and the outworks that enclosed the entire fort.
The fort was later abandoned before being re-established in 1793. During the latter part of the 19th century, the external barracks were demolished. In 1875, the fort's covered way had sheltered passages added. The fort was decommissioned circa 1900.
During World War II the Germans occupied the fort. They added some blockhouses in the ramparts and on the seafront. From 1948, the fort became the administrative block for a development of vacations homes, but was closed in 1977.
References:Ehrenbreitstein Fortress was built as the backbone of the regional fortification system, Festung Koblenz, by Prussia between 1817 and 1832 and guarded the middle Rhine region, an area that had been invaded by French troops repeatedly before. The fortress was never attacked.
Early fortifications at the site can be dated back to about 1000 BC. At about AD 1000 Ehrenbert erected a castle. The Archbishops of Trier expanded it with a supporting castle Burg Helferstein and guarded the Holy Tunic in it from 1657 to 1794. Successive Archbishops used the castle's strategic importance to barter between contending powers; thus in 1672 at the outset of war between France and Germany the Archbishop refused requests both from the envoys of Louis XIV and from Brandenburg's Ambassador, Christoph Caspar von Blumenthal, to permit the passage of troops across the Rhine.