A window from the house in Grignan, France.

Grignan has had several archeological excavations have shown that the rocky promontory of Grignan has been occupied since the Iron Age. An ancient Bronze Age society once existed here, and Roman occupation occurred here in the 5th and 6th centuries AD as well. In the year 1035, a cartulaire (a ledger of church or monastery property titles) from the Abbey of Saint-Chaffre in the Haute-Loire mentions an obscure castellum Gradignanum, which is said to be a reference to an obscure castellum Gradignanum. The name gradually evolved over the next century into the castrum Grainan (1105), then Graigna, Grazinam, it is unknown when the castle was built. It is unclear who built the castle or when it was built, and very little is known about its beginnings or its builders. There has been some evidence of the existence of a certain Christophe de Grignan somewhere around the year 1030. In 1035, the cartulary of Saint-Chaffre, speaks of a certain Rostagnus de castello Gradignano, or 'Rostaing du château de Grignan.'