Skull and mail coif, Visby, Sweden, 1361 AD
https://en.wikipedia.org/wiki/File:Fornsalen\_-\_Invasion\_1361\_-\_Schädel\_mit\_Kettenhaube\_1.jpg
I think this link is broken.
https://commons.wikimedia.org/wiki/File:Fornsalen\_-\_Invasion\_1361\_-\_Schädel\_mit\_Kettenhaube\_1.jpg
Obviously that didn't protect him enough, he's dead