Odo de Barri built the first castle at Manorbier, in the C11, an earth and timber fortification which his son, William de Barri, refortified in stone during C12.

William's son was Giraldus Cambrensis who described the castle as "excellently well defended turrets and bulwarks, and is situated on the summit of a hill extending on the western side towards the seaport, having on the northern and southern sides a fine fish-pond under its walls".

Manorbier Castle's main claim to fame is as the birthplace of Gerald of Wales, son of the Norman sir William de Barri. The father of William, Odo de Barri