The Beaucastel family were living in Courthezon by the middle of the sixteenth century. In 1549 "Noble Pierre de Beaucastel" bought "a barn with its plot of land extending to 52 saumees at Coudoulet".
Later, the manor house that we know today was built here and you can still see the arms of the Beaucastel family sculpted in stone in one of walls of the drawingroom. The Beaucastels were among the more notable families of this little town and in 1687 Pierre de Beaucastel, in recognition of his conversion to Catholicism after the revocation of the Edict of Nantes, was appointed "Capitaine de la ville de Courthezon" by Louis XIV. The letter from Louis XIV, also signed by Colbert, to Pierre de Beaucastel is still in our possession.