 The head was then mounted on the walls of the newly built church to scare off evil spirits, and used for protection.In commemoration of St. Romain, the Archbishops of Rouen were granted the right to set a prisoner free on the day that the reliquary of the saint was carried in procession (see details at Rouen).The term "gargoyle" is most often applied to medieval work, but throughout all ages, some means of water diversion, when not conveyed in gutters, was adopted.