The first written mention of Chillon Castle dates back to 1150. At that time, the castle was owned by the Counts of Savoy. It was in a very strategic location, nestled between the mountains and the lake, on a connecting route from the north to the south – the Via Francigena. The Savoy family controlled the route that passed in front of the castle and led to the new town of Villeneuve, a path trodden by travellers, merchants and pilgrims heading towards Rome via the Great Saint Bernard Alpine Pass. The Counts of Savoy profited from this thoroughfare by installing a toll to cover security and maintenance costs for the road.
In the 13th century, Peter II of Savoy turned the castle into a summer residence. The underground vaulted Gothic ceilings mainly covering the wine cellars and the pantry were usually reserved for cathedrals, giving Chillon a unique twist. In the latter half of the Savoy period, a prison was built around the stone pillars and protruding rocks; the famous jail said to have housed Bonivard, a converted protestant priest who opposed the catholic Savoys, and was imprisoned here for six years.
The Savoy dynasty furthered their conquests of the Pays de Vaud until their domination spanned two-thirds of the territory which makes up today’s French-speaking Switzerland. Since the Counts had to move around to govern and liaise with their subjects, they appointed a castellan to take up permanent residence at the castle and handle their affairs.
Chillon was gradually cast aside by the Savoy court in favour of other castles. In 1436, Amadeus VIII attempted to revive the castle before being summoned to the papacy under the name Felix V. He sent his master architect, Aymonet Corniaux – a carpenter tasked with building maintenance across Chablais and the Pays de Vaud – to carry out major works and modify the defence mechanisms on top of the towers and ramparts. These plans were short-lived and Chillon would be left derelict until the arrival of the Bernese in 1536.