I watched the movie Troy last night and I noticed that some of the helmets had things that looked sort of like brushes on them.
Were those helmets actually used or is it a Hollywood thing ? If they were used what was the purpose, was it decroative or were the brushes used to clean the armor or something ?
I’m no expert, but I presume the plumes were an aid to identification. Bright, visible plumes would make it easier to spot your units, judge your casualties and so on.
It was a style, and also used to denote rank. Some Greeks wore them, some didn’t. Same for the Romans.
Normally no one would want any kind of obstruction on a helmet or other armor - it might catch a hold a blow that you might want to deflect. Not for nothing are modern tanks designed with sloping armor - a shell will tend to follow the bath of least resistance, and might follow the curve and glance off harmlessly. But a horsehair crest would make you look taller, fiercer, and just plain cool.
An enlisted man would have a front to back crest, the kind we see most often. An officer would be distinguished by a sideways crest, which, thanks to a million movie scenes, looks somewhat dopey to us now. I suspect movie makers seldom used a sideways crest (assuming the knew the difference) because it might have a little busy and distracted from the star’s handsome face.
Most of the ancient helmets I have seen in musuems have no holes or brackets or anything where the crests would have been attached.
But quite a few books by people whom I assume would be knowledgeable (cf. Barry, Warfere in the Ancient World) show crestsa as well as the occasional painted helmet. So do many vase paintings.