So I know it says so in my 'About Me' page that I trained in Millinery, but I haven't shared hats here that much.
So this is a medieval hat, known as a 'callotte'. Made by me, obviously, so a modern interpretation, not an extant piece.
The hat is made in a dark blue felt. The crown is blocked on a round hat block, and then the upturned brim is cut and then shaped by hand.
In fact, come to think of it, the whole hat is made by hand - hand blocked, hand shaped, and completely hand sewn.