Great Saint Bernard Pass. A charter of 1150, in which Count Humbert III granted the Cistercians of Hautcrêt free passage to Chillon, names the owner of the castle as Gaucher de Blonay, a vassal of the Count of Savoy within the feudal society of the time. From the mid 12th century, the castle was summer home to the Counts of Savoy, who kept a fleet of ships on Lake Geneva. The castle was greatly expanded in 1248 and 1266-7 by Count Peter II. During this time the distinctive windows were added by Master James of Saint George, who is believed also to have added similar windows to Harlech Castle in Wales at a later date. Chillon as a prison During the 16th century Wars of Religion, the dukes of Savoy used the castle to house prisoners. Its most famous prisoner was probably François de Bonivard, a Genevois monk, prior of St. Victor in Geneva and politician, who was imprisoned there in 1530 for defending his homeland from the dukes of Savoy. Over his six-year term, de Bonivard paced as far as his chain would allow, and the chain and rut are still visible. Bernese period In 1536, the castle was captured by a Genevois and Bernese army, and all the prisoners, including de Bonivard, were released. The castle became the residence for the Bernese bailiff until Chillon was converted into a state prison in 1733. Vaudois period In 1798, the French-speaking canton of Vaud drove out the German-speaking Bernese authorities and declared the Lemanic Republic. The Vaudois invited in French troops to help them maintain autonomy from the other Swiss. When the French moved in and occupied, Chillon was used as a munitions and weapons depot. Restoration Some restoration efforts on the Castle in the 19th Century, inspired by the Romantic vision of aesthetics, sacrificed historical veracity. At the end of the 19th century, a systematic restoration of the monument was undertaken, through which an ethic of monumental restoration was developed in one of the first cases of the application of archaeology and history to rebuild a structure in a historically accurate way. This was possible because of the combination of four factors: The involvement of pioneering specialists in restoration including Johann Rudolf Rahn, one of the founders of the Swiss Society of Historical Monuments in 1880, and , a specialist in Renaissance architecture who was closely associated with the