To understand why and how military helmets evolved in medieval England this paper will analyse key details of two helmets, namely the Benty Grange helmet, a seventh-century Anglo-Saxon artifact, and the Pembridge helmet, a fourteenth-century English artifact. Key details include construction methods, construction materials, defensive features and iconography, which if analysed together can help to explain why the design of helmets changed so dramatically over this seven hundred year gap of time.