Imperial noble consort (Chinese: 皇貴妃, Vietnamese: hoàng quý phi, Korean: 황귀비) was the title of women who ranked second to the Empress in the imperial harem of China during most of the period spanning from 1457 to 1915.
In Ming Dynasty, the rank of Imperial Noble Consort was only a highest honorary title of an imperial consort.
On the contrast, in Qing Dynasty, the rank of Imperial Noble Consort was considered to be Vice-Empress, making the rank closer to the Empress, therefore, the Emperor was very careful in promoting one of his imperial consorts in this rank while the Empress was alive. If the Empress agrees to the promotion of an imperial consort to Imperial Noble Consort, it should be in the following causes:
When an imperial consort, (usually a noble consort), was gravely ill, the Emperor promotes to her to Imperial Noble Consort to pray for her and to comfort her.
The Imperial Noble Consort will help the Empress as assistant in managing the inner court.
If the Empress was incapable of ruling the Imperial Harem or she died, the Imperial Noble Consort will take over her duty as chief of the Imperial Harem.