Generic term for crenallations of timber and/or stone. They were added to buildings to give cover to defenders. Crenallating, the act of building crenallations, required a licence from the Monarch without which a castle was classed as unofficial (as for Nafferton, Northumberland). Loopholes could also be used to drop heavy items onto attackers from battlements. Battlements were frequently added to follies and buildings called a ferme ornee to give a (false) air of age and grandeur.