Calderwood Castle in the opinion of many genealogical groups is thought to have been anciently possessed by a family bearing the name Calderwood. In fact Calderwood is so ancient a title that it predates Castles in their modern interpretation. The documents regarding the ancient lands of Calderwood and family are scarce, but do suggest that the name descends from a small village or possibly a defended iron-age town (oppidum) as referred to in marriage charters. There were several Calderwood landholdings in the area, and the retainers on the lands would have gone by this name, rather than any fortification at the Dee of Calder.