Archaeological excavations have shown that the first castle on the site was a Norman motte and bailey, built sometime in the mid 11th century. Following the Norman Conquest, the Umfraville family took over control of the castle. Robert d’Umfraville was formally granted the barony of Prudhoe by Henry I but it is likely that the Umfravilles had already been granted Prudhoe in the closing years of the 11th century. The Umfravilles (probably Robert) initially replaced the wooden palisade with a massive rampart of clay and stones and subsequently constructed a stone curtain wall and gatehouse.