In ancient times, emperors, governors, and doctors all wore big gift crowns when they held sacrificial ceremonies. It's black outside and vermilion inside. There is a rectangular plate on the crown top, called extension, which is high at the back and low at the front, and slightly leans forward. The front end of the delay is decorated with several strings of small round jade, which is called Xi. When the bun is crowned, a long hair card should be inserted horizontally to avoid the crown. A small ribbon is tied around the chin at both ends of the basket, called ribbon; They also hung a cotton pill called a pill with a silk rope called a pillow, and the lower end of the pill was decorated with jade, called a pill. Because the rafters are right and left ears, they are also called ears and ears. Song and Li are all part of the crown. The crown of the son of heaven is twelve (it is said that there are twelve before and after), nine princes, seven doctors and five doctors. The system of past dynasties is roughly the same. After the Northern and Southern Dynasties, only emperors could wear crowns because of the ceremonial crowns used to address emperors. Huai Nan Zi. Main skill training ":"The king of ancient times, before the crown. " Gao: "The crown is the crown of the king." Tang Wang Wei's "Work with Jia Zhishe in Daming Palace": "The nine gates of heaven reveal the palace and its courtyard, and many countries bow their pearls."