Steel with leather lining and trim. Most likely worn by auxiliaries. Originally found in a cache at the Roman fort in Hungary.

The classic ‘Imperial Gallic’ helmet of the early Roman Empire gradually faded out during the turbulent 3rd Century AD. The two most common helmet types after this were the ‘Ridge’ and ‘Spangenhelms’.
The Ridge helmet probably made known to Romans when this region was under the rule of the Sassanids. This distinct helmet examples are widespread and found as far apart as Hungary, the Balkans, Holland and Britain.
The spangenhelm is one where the construction of the dome uses more or less equal sized segment converging on a point on the very crown of the dome. Examples are found throughout Europe and the middle east.