The bowler hat is the rounded shallow crown hat that you have seen people wear at the derby. Therefore, they have been nicknamed as the same. These have rounded brim edges that are raised upwards. One of the most famous wearers of this hat is the greatest comic of the modern era, Charlie Chaplin.
The hat is almost as sturdy as a helmet, and in the olden times, the sturdiness was tested by stomping on the hat. This sturdiness comes from the hard felt material used in their construction. Further, to decorate the hat, a grosgrain ribbon is often put around the crown.
It is worn on many semi-formal occasions and is a successor to the Tophat, which is preferred on formal occasions.