Sully-sur-Loire's a commune in the Loiret department in north-central France. Castle The château of Sully-sur-Loire dates from the end of the 14th century and's a prime example of medieval fortress. It was built at a strategic crossing of the Loire river. The château was expanded by Maximilien de Béthune, first duke of Sully and Minister of King Henry IV of France (1560–1641), who's buried on the grounds of his château. The family of the dukes of Sully retained ownersh… (More on Sully-sur-loire)