Shield Boss

A shield boss is the round, convex or conical piece of material at the centre of a shield. It is usually made of metal although wood and leather could be used. A spike for offensive purposes could also be incorporated in the design. the purpose was originally to cover the mounting for the shield's grip on the reverse but became ore ornamental as centred grips were replaced by gripping straps (enarmes) fixed to the back of the shield.(Wikipedia 11/2/2020)