medieval kettle hat crispinIn the early 14th century, kettle hats like this one with sloping brims emerged. Advances in metalworking made it cheaper to produce kettle hats from a single piece. The brim of the kettle hat became more sloped, allowing it to deflect projectiles from above. This reduced the impact on both the helmet and the head. This type of helmet was so effective that even aristocrats wore it. The brim provided protection against downward blows and projectiles.