The Chaperone is soft fabric hat worn in medieval northern Europe, it consist of a ring fabric around the head, a crown of loose fabric and long scarf like tail called a liripipe thrown over the shoulder.
The Chaperon developed from a woollen hood, where the hole for face in the hood ended being rolled until it become the band around the head and the large open neck hole becoming the cape hanging from the top.
A touted reason for this is possibly because it was cooler to wear it that way in hot weather.
The hood evolved and became a actual style of hat that we call the Chaperon worn by the wealthy and nobility in the 13th to 15th Centuries, until it went out of fashion around 1480
Chaperons continued to evolve as the one I'm wearing here with the ring of fabric which was once a rolled up hood becoming padded Bourrelets around the the head in some cases growing almost turban like in proportions and cornette or cape which is the loose fabric hanging from the padded ring and the liripipe becoming extremely large and flamboyant.
Most contemporary portraits show Chaperons in one colour of fabric, but the belief is that was just the simplify the artist job since extravagant fabric from silks or damask were listed as being used.
One thing I note in England particularly during this period the chaperon was also a name for some styles of hood as well as the head covering I'm wearing here