This impressive medieval fortress is listed as a Historic Monument, and the reflection of its distinctive architecture can be seen in the still waters of its moat. Behind its military fortifications the château conceals an elegant Renaissance interior created by its famous owner, the Duke of Sully.

Few châteaux have undergone quite so many architectural modifications as Sully-sur-Loire. The earliest remains from the château date from 1102, when it was a defence outpost on the left bank of the Loire.

In 1218, Philip Augustus took advantage of a disagreement between the lord of the land and the bishop to seize the place for a brief period and build an imposing cylindrical tower which unfortunately no longer stands. The château was damaged by high flood waters in 1363 and later changed hands after the sole heiress married Guy de la Trémoïlle. The latter began a long renovation process and entrusted royal architect and designer of the Louvre, Raymond du Temple, with drawing the new plans. He notably commissioned work on the keep, which was built both to defend the bridge over the Loire and to host lavish feasts which he threw for high-profile guests. Joan of Arc stayed at Sully twice during this period in order to visit King Charles VII while he was in the château. The site was later badly damaged during the French Wars of Religion and left to ruin.

Fortunately, it was bought and saved in 1602 by Maximilien de Béthune, then Minister to Henry IV, and the château has remained in the same family ever since for a period of four centuries. The Great Sully, as he was known as, launched a large-scale renovation project on the Renaissance interior and the exterior of the château, including the creation of the adjoining park. The artillery tower was also built at this time and connected to the château by two covered galleries, while a third linked the keep to the small château. For the first time, the site was fully enclosed by the surrounding outer wall.

From the 18^th century onwards, the Château of Sully-sur-Loire was subjected to numerous demolition and re-construction projects which gradually transformed its layout. Several buildings were removed, while new ones were built such as the sumptuous main residence section. The 20^th century also saw major architectural modifications. The tops of the Eastern towers were renovated just before a terrible fire destroyed the wing built in the 18^th century. The château was listed as a Historic Monument in 1928 but sadly suffered damage during the Second World War. It was bought by the Loiret département in 1962 and new renovation projects were launched.

Despite its turbulent history, the château still preciously guards its greatest treasures including the chemin de ronde (patrol route), a wall hanging depicting Psyche, its 14^th-century barrel-vaulted ceiling and furnished rooms as well as the grave of the eminent Sully himself. The visit route has been thoughtfully and skilfully designed, guiding visitors past paintings and tapestries and amid period furnishings. It is a fascinating visit that is enhanced by the different exhibitions and events organised throughout the year.