'Hi James, my older daughter wants to know why gladiator helmets have a brush on top of them? We saw a video of you fighting with a brush on the helmets.'
-Mother Interior
Thanks for the prompt.
I began building helmets for stick-fighting and machete dueling and waster sparring in 1999.
The hockey helmets worked great, once we closed the face cage in, but the flat and rounded top, split from descending vertical chops and slashes. Since we were doing gladiatorial recreations at events, I got some dollar store feather dusters that had a wire core, a twisted steel wire, and used these to make crests. Bryan used a broom head on his! Robert used a brush.
We soon found out that descending strokes just glanced off and did not bite the top of the helmet.
With sticks keen timing is required to punch through gear and any small deflection ruins the stroke. We found that hanging leather belts or even just a flannel shirt from the belt cut way down on leg bruises when fighting with the heavier weapons. It also caused drag on the shoulder of the stroking hand.
With the blades, it was even more effective, for the slightest glance of a blade takes the edge off target.
In ancient times, this would be even more important, to have deflection, since they did not have helmet liners—though an afro would help—and the fact that the metal was thin and that descending strokes from horsemen were gravity-powered and gained access to the crown of the helmet.
It does place more stress on the head, having a heavier helmet, so a horsehair crest or even a horn, would be much better than building up a metal crest like the helmet of the Thraex or the Myrmillo, which had a ceremonial and metaphoric significance.
There is also the signification feature. A soldier would have a crest that ran from above the forehead to the back of the head, and an officer would have a crest that ran from ear to ear.
Modern academics who have not fought, let alone fought on foot against horsemen, have no idea about this and assign a crest mere ceremonial significance. Even having a rock dropped on your head could be made less terrible by a crest encouraging it to roll to one side.
Weather made of metal, hair, wood, feathers or rope, a crest helps deflect and pad blows on helmets that fit the head closely with little of the suspension system enjoyed by football players, iron workers, hockey players, river kayakers or bull riders of today.
In one case the crest [a fin] was a disadvantage, as it was designed to make the Myrmillo gladiator into a two legged fish that could be netted by the Retiarius. So that fighter was in danger of being netted and blinded by his dedicated foe with the net and trident.
Remember, in real peril, anything worn on your head when hard objects are coming your way, is helpful. A hat was all I wore when I started stick-fighting, to cut down on impact and cuts.