Weight: 0.3-0.5 kg
The iron or steel skull-cap was perhaps the closest-fitting of all medieval helmets. It was designed to sit very close to the wearer’s head, with only a very thin material lining.
The skull-cap could be worn as the only head defence, being clearly better than nothing at all. It could help prevent blows from actually cracking, splitting or slashing open the head, but it could not prevent concussion.
In an effort to make it more effective many fighting men wore it either under or over a mail coif . This meant that several layers of material were working together to protect the head.