I was browsing wikipedia and came across this picture: https://en.wikipedia.org/wiki/Roman%E2%80%93Persian_Wars#/media/File:Bas_relief_nagsh-e-rostam_al.jpg
The Sassanid king appears to be wearing a recognizable sort of crown with pointed-sides, similar to generic crowns I commonly see in video games. When did crowns of that sort first come into use?
I don't think this image shows a proto-typical crown. The bulb shape you see above and behind is most likely part of the headdress, since other images of Royal Iranian headdresses from this era clearly incorporate it.
To me the diadems found in Mycenae Greek Royal tombs (circa 16th c. BC) look like proto-typical crowns, but I can't locate a good authenticated contemporary image of one being worn to confirm whether they would have been used as found, or whether other elements would be added.
