The present Château de La Roche-Guyon was built in the 12th century, controlling a river crossing of the Seine. In the mid-13th century, a fortified manor house was added below. Guy de La Roche fell at the Battle of Agincourt, and his widow was ousted from the Roche, after six months of siege, in 1419; she preferred to depart rather than accept Henry Plantagenet as her overlord. It came to the Liancourt family with the marriage of Roger de Plessis-Liancourt to the heiress Marie de La Roche; he was a childhood companion of Louis XIII, first gentleman of the Chambre du Roi, and was made a duke in 1643. He and his wife made great changes to the château-bas, opening windows in its structure and laying out the terrace to the east, partly cut into the mountain's steep slope.
The domain of La Roche-Guyon came to the La Rochefoucauld family in 1669, with the marriage of Jeanne-Charlotte de Plessis-Liancourt with François VII de La Rochefoucauld. The Château retained its medieval aspect of a fortress, with its moat and towers and cramped, dark living apartments. The Château was largely extended in the 18th century.
After D-Day in World War II, German Field Marshal Erwin Rommel defended Normandy against the Allies in World War II from a bunker located here. The castle also was Rommel's headquarters.
Restorations and archaeological surveys undertaken after 1990 by the Conservatoire régional des Monuments historiques revealed new additions to the documentary history of La Roche-Guyon, undertaken in the 19th century by Hippolyte Alexandre and Emile Rousse.References:
The Petersberg Citadel is one of the largest extant early-modern citadels in Europe and covers the whole north-western part of the Erfurt city centre. It was built after 1665 on Petersberg hill and was in military use until 1963. It dates from a time when Erfurt was ruled by the Electors of Mainz and is a unique example of the European style of fortress construction. Beneath the citadel is an underground maze of passageways that can be visited on guided tours organised by Erfurt Tourist Office.
The citadel was originally built on the site of a medieval Benedictine Monastery and the earliest parts of the complex date from the 12th century. Erfurt has also been ruled by Sweden, Prussia, Napoleon, the German Empire, the Nazis, and post-World War II Soviet occupying forces, and it was part of the German Democratic Republic (East Germany). All of these regimes used Petersberg Citadel and had an influence on its development. The baroque fortress was in military use until 1963. Since German reunification in 1990, the citadel has undergone significant restoration and it is now open to the public as a historic site.