The town of Gien-le-Vieux (Old Gien) became a parish in the high Middle Ages when Saint Peregrine, bishop of Auxerre, founded the Church of St. Peter and St. Paul. In 760, the army ofPepin the short stopped at Gien-le-Vieux before going to fight againstGascony andAquitaine. In the eighth century, Charlemagne authorised the construction of a fortified mound around the site of the present castle.
In the ninth and tenth centuries the decline of the Carolingian empire and Viking Raids led to a gradual abandonment of Gien-le-Vieux. The population mostly moved to the site of the current town of Gien which was easier to defend. However, the church of St. Peter and St. Paul survived until the seventeenth century.
Gien had a large Protestant community and like its neighbours, Châtillon-Coligny, Châtillon-sur-Loire and Orleans, it was a Protestant stronghold during the French wars of religion. During this period, the churches were looted and clergy hunted.
Much of Gien was destroyed during theSecond World War. The town was bombed by the Luftwaffe, who aimed to destroy the town's bridge to prevent the French Army from retreating. The bombardment created a huge fire which completely destroyed over four hundred buildings, including the town's two main churches. The town was rebuilt after the war.