Castelnau means châteauneuf, "new castle". It's a proud fortress, on its rocky spur! Hugues of Castelnau was mentioned for the first time in 1076: he altered his castle. When crusade against the Cathars came, Castelnau belonged to count of Toulouse, then later became a fief of Turenne's castle. The lord of Castelnau gave Turenne, each year, the tax of... an egg!
In 1295, Matfred of Castelnau married Alasie de Calmont. A rich marriage... at that time, the castle was converted into a nice residence: a fortress flanked by towers on angles, with a square keep (13th century) in the middle; a wide moat surrounding the walls plus a second wall.
Pons de Caylus inherited the castle in 1396. Jean de Caylus, one of his descendants, who hold a place in Cahors episcopal see in the middle of the 15th century, gathered a council in the castle, which expelled all the English troops from Quercy area.
Then our castle fell to the Clermont-Lodève family: it was entirely refit in the 17th century. But the owners left Castlenau and went to Versailles... Fell to the Luynes family in 1718, Castelnau was abandoned to farmers, who damaged it. In 1844, they wanted to demolish it.
But 7 years later, a fire destroyed the castle... Unfortunately, the gorgeous 17th century apartments disappeared in the blaze... Nowadays, we can visit Castelnau, since it's the France Nation's property!