The old town of Grandson owes its development to the two most remarkable monuments of the city: the castle and the church.
Although the area has been inhabited since prehistoric times by the Lacustres, the development of the town of Grandson dates back to the 11th century. At that time, the powerful family of Grandson erects the castle and the church, two important monuments around which is built the town. In the 12th century, the lords of Grandson gave the church of Saint-Jean-Baptiste to La Chaise-Dieu, the most important abbey of the Benedictine order after Cluny. The arrival of the monks amplifies the development of the old town of Grandson, which is surrounded by walls around 1300.
After centuries of prosperity, the Grandson family disappeared in the late 14th century. During the following century, the town and the castle is handed from the Maison de Savoie to the lords of Chalon. This period is marked by fires, frequent in the Middle Ages. Following the famous Battle of Grandson against the Burgundians, the town passes under the rule of Bern and Fribourg, before returning to the Vaudois during the independence of 1798.