 The helmet is dated to the first half of the first century AD, based on the style of the acanthus scroll on the back of the helmet, and other objects found with the helmet and in the tombs nearby.It is the earliest known Roman helmet with a face mask, and is broadly classified as a cavalry sports helmet—type D, according to the typology put forward by H. Russell Robinson.Type D helmets are characterised by a single horizontal hinge attaching the face mask to the head piece, and by head pieces that are decorated to represent helmets.