[defrost]

Helmet usage, as in protective headware for general melee war and one on one fighting, dates back to the bronze age.

Hard hats, of assorted kinds for general protection while working, date back to the 1890s and became more commonplace ~1920 (ish) onwards in construction, mining, and ship building industries.

* Helmets: https://www.battlemerchant.com/en/blog/the-evolution-of-hist...

* Hard Hats: https://en.wikipedia.org/wiki/Hard_hat

I suspect there are more early European hard hat examples to be found than are cited in the wikipedia article.