There is no hierarchy.
The term "Three Palaces and Six Courtyards" comes from the architecture of the Forbidden City. The "Three Palaces and Six Courtyards" are all located in the inner court of the Forbidden City.
The "Three Palaces", also known as the "Three Back Palaces", refer to the Qianqing Palace where the emperor lives, the Kunning Palace where the queen lives, and the Jiaotai Palace (the name of the palace) located between Qianqing Palace and Kunning Palace. Taken from the "Book of Changes", it means "the harmony of heaven and earth, the harmony of peace and prosperity". The iron sign "No interference in political affairs in the inner palace" is erected in this hall)?
The "Six Courtyards" are actually ten. Second House. The "Three Palaces" each have six palaces on the east and west roads. The "Six Palaces on the East Road" are Jingren Palace, Chengqian Palace, Zhongcui Palace, Jingyang Palace, Yonghe Palace and Yanxi Palace; the "Six Palaces on the West Road" are : Yongshou Palace, Yikun Palace, Chuxiu Palace, Xianfu Palace, Changchun Palace, Taiji Palace (Qixiang Palace). Because each palace is a courtyard-style building, it is called "East Sixth Courtyard" and "West Sixth Courtyard".
Extended information:
As far as the palace system of the Qing Dynasty is concerned, the palace system was truly established during the reign of Emperor Kangxi. It was stipulated that the queen should be in the middle of the palace and take charge of internal governance. There should be only one imperial concubine. , two noble concubines, four concubines, and six concubines, living in the sixteen east and west palaces respectively, assisting the empress in governing the house. There are also nobles below the concubine, who are always there, and who have agreed to the third level, all of whom have no fixed number. They live in the east and west palaces and practice diligently. Internal position.
Reference: Baidu Encyclopedia-San Gong Sixth Academy