This is sort of brimless cloth hat is a bit odd, it could have been worn in any period from the 13th to 19th century, although I've grouped it in the so-called renaissance, 16th C period
The hat is made like a muffin cap with an abundance of material fixed to a smaller headband, this one is made so the headband becomes hidden when worn.
The fabric green in colour is slightly eccentric style make this something that could be worn by a medieval scholar or a poet
Found for £2 in the bargain bin at a lrp fair