It dates from the 1518th century, between 1521 and XNUMX. It was Denis Briçonnet, prior of Coussay and bishop of Saint-Malo, who decided to build a hotel on the priory that had existed since the XNUMXth century, which he would make his home. The priory of Coussay thus became one of the first castles of the Renaissance.
Before being enthroned Cardinal de Richelieu in 1622 and having responsibilities that kept him at court, he stayed many times in Coussay. He is going to make changes to the castle. After the Revolution, the castle will change owners many times and be somewhat abused. At the beginning of the 1949th century, the castle was bought by a notary from Mirebeau who undertook work to rehabilitate the building. In XNUMX, the facades and roofs of the castle, the moats and their corner turrets as well as the Richelieu oratory were classified as Historic Monuments.