aah I didn't see the 12th century (and I know it's not a good model) but in other crusades it was used but mainly used of the cav cause of the flat top
Edit: all sources that I can find says that it was common from 12-13th century in most european armies the type of helmet is called great helm
Edit: all sources that I can find says that it was common from 12-13th century in most european armies the type of helmet is called great helm