The first mention of the castle appears in the archives in 1159 under the name of Villa Santi Desiderii - Villa de Saint-Didier. It was around 1500 that the seigniorial residence, built on the foundations of a gallo-roman villa, began to develop under the impetus of the Marquises of Thézan-Venasque, who invested the premises, transformed them and enlarged the original habitat, which gradually became a castle.
The main residence of this illustrious family from 1545 onwards, the castle, which stands on the edge of the village of Saint-Didier, takes on the appearance of a beautiful renaissance residence.
During the 17th century, Louis de Thézan, elected to the county nobility in 1660, and his son Paul-Aldonce-François, were particularly involved in major modernisation work, enhancing the prestige of the old Renaissance residence.
The building is considerably enlarged by the construction of a building erected on the remains of the old ramparts.
The project adopts the appearance of a building flanked by two wings connected by a vast terrace, typical of 17th century classical constructions.
Several ceremonial rooms were fitted out in these wings and decorated with pomp and circumstance.
Another transformation, fundamental in the history of the castle, is the change in the axis of the entrance at this time. The main entrance, which had previously been to the south towards the neighbouring village of Le Beaucet, is now directed towards the fortified tower of Saint-Didier.
This change goes hand in hand with the creation of a real enclosed garden to the south.
Due to its structure, organisation and regular layout, characteristic of a formal garden, its design is attributed to André Le Nôtre, who was then active in the region.
In 1809, all of the property was sold at auction following the death of the last Marquise de Thézan, who had died without descendants.
Her niece, Olympe de la Baume-Suze, acquired the estate. She sold it in 1814 to Louis, Marquis Pelletier de Gigondas de La Garde.
The Marquis, accustomed to a sumptuous lifestyle, undertook extensive decoration and comfort work to restore the castle to its former glory. These receptions will make the reputation of Thézan beyond the regional borders.
His son Henri succeeds him and continues the embellishments. He was responsible for transforming the southern façade into a fashionable neo-medieval style, giving it a romantic charm. It was at this time that the french garden was given the appearance of an english park. Ruined by an expensive lifestyle, he was forced to sell the castle in 1862.
It was Adolphe Masson, a Doctor from Carpentras, who bought it to establish a hydrotherapy centre. Numerous rooms and treatment rooms were created and the remarkable rooms were decorated with new decorations.
On his death, his son-in-law, Dr Masquin, succeeds him at the head of the establishment. He did not fail to add to the medical merits of the health centre the pleasure of worldly leisure. The "baths" are modernised to the great pleasure of the curists, attracting an increasingly wealthy clientele.
Throughout the 20th century, the hydrotherapy centre continued its activity. Its reputation did not falter.
Gradually transformed into a clinic for rest and care of nervous diseases, it closed its doors at the end of the 1980s and was moved to a more contemporary building, which is still in use in Saint-Didier.
Gradually, the castle and its garden fell into disrepair.
Having suffered the ravages of time and acts of vandalism, the property was in a real critical state when we purchased it in april 2019.


A campaign lasting several years was launched with the aim of bringing the estate back to life and opening it to the public.
The gamble paid off: the Château now welcomes thousands of visitors, who have become its best ambassadors!

The Château is now inhabited all year round, and we are now able to open up some of the historic rooms, which we have carefully emptied, cleaned and furnished for the enjoyment of visitors.