File:Medieval rotary key (front, reverse) - (FindID 251638).jpg

English: Cast copper alloy rotary key. Medieval (c.14th/15th). Length: 76mm; width (top of the bow to the bottom of the bit): 29mm; depth: 8mm; mass: 29.5g. The key consists of a portion of the bow, the shank, and the slightly incomplete bit. The bow has a curved internal and external edge, which slightly thickens towards the top. There are shoulders where the bow joins the shank. The shank is oval in section with a perforation within the bit-end. The top of the shank is incomplete, exposing this perforation which tapers towards the bow. The bit has a central drop shaped cavity below the shank, and a ward on one side. There appears to be a cleft at one end, and possibly a further cleft at the bottom of the bit, but as it is incomplete this is unclear. The rotary key has a pitted green patina. In the Museum of London's “Medieval Catalogue" (1940 p133-144), Ward Perkins has introduced a classification system for door and chest keys. The key described in this record is most closely related to his Type VI. Ward Perkins describes the type: “They are characterized by the solid shank, bored at the end to leave a conical hole, by the massive bit, and by the elaborate form of the bow. The latter may be lobed or lozenge-shaped or a combination of both, and occasionally the corners of the lozenge are elaborated…” (p140). Ward Perkins dates a number of closely related copper alloy keys of Type VI to the 14th and 15th centuries, and this may be an appropriate date range for the key recorded here.