Empresses were divided into eight grades in Qing Dynasty, namely: Empress, Imperial Lady, Imperial Lady, Concubine, Concubine, Noble Person, Constant Attendance and Youwei. The imperial concubine is the first class, the imperial concubine is the second class, the princess is the third class, the concubine is the fourth class, the noble is the fifth class, often the sixth class, and the infinite is the seventh class.

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When a female practitioner enters the palace, she usually promises her. Then some of them were promoted to regular customers, concubines, concubines and nobles. Noble people and above are produced from the dignitaries of past dynasties. Noble people and below only need to choose from the children who worship Tang A, and some are accompanied by royalty or grandchildren. As for the empress, Empress Dowager Cixi usually chooses from the daughters of the nearest princes and ministers and is canonized by the emperor. The emperor can change it if he doesn't like it in the future.

The Qing dynasty regarded the election of empresses as an important politics. The Qing dynasty chose empresses, mainly Manchu, followed by Mongolian nobles, in order to strengthen ties with Mongolian nobles. The concubines of Qing Dynasty compiled by Tong Xun and Hou Jiuxuan according to the Four Classics of Qing Royal Family lists 187 concubines. Except for the eight unmarked surnames, 12 is nuzhen, and 136 is Manchu and Mongolian.

References:

Baidu Encyclopedia-Empress System in Qing Dynasty