Generally speaking, the empress dowager of the Qing Emperor, or the daughter of the nobleman from the Mongolian confederation, or the lady from the Eight Banners family, very few wrapped slaves can sit on the throne of the Empress of the Qing Dynasty, but there are exceptions to everything, and the only one who has the status of a coat and enters the middle palace is Empress Xiao Shurui.
First of all, let's look at the family lineage of Empress Xiaoshurui.
Empress Xiaoshurui's surname was Hitara, a Manchurian Zhengbaiqi person, and the daughter of the Minister in Charge of the Ministry of Internal Affairs, the Deputy Governor and Erjing'e.
The Hitara clan is a very old surname in Manchuria, this family has a deep relationship with the Ai Xin Jue Luo clan, the Qing Taizu Nurhaci's birth mother Empress Xianzu Xuan is from this family, therefore, the Hitara clan has a high status in the Nurhaci and Emperor Taiji periods, known as the "uncle family".
After the Qing Dynasty entered the Guan, some of the clan moved to Guannei, and due to the small number of people, they were incorporated into the Zhengbai Banner Officiating clothing of the Ministry of Internal Affairs, and Empress Xiaoshurui belonged to the branch that moved to Guannei and was assigned to the wrapping. This branch did not have any major figures during the KangYong period, until the Qianlong Dynasty, there was a university scholar named Laibao, who was empress Xiaoshurui's uncle.
It was precisely because of laibao that this Kitara coat in Guannei was carried to the Manchurian Zhengbai Banner in the early years of Qianlong.
In the thirty-ninth year of Qianlong, Qianlong temporarily ordered an additional draft, the purpose of this draft was to give his son Yongyan the choice of Concubine Fujin, after some selection, Qianlong finally selected Empress Xiaoshurui. However, Qianlong's marriage this time may really have the purpose of covering up the crown prince, you can look at the family lineage of Qianlong's other sons Fu Jin.
The eleventh son of the Emperor, Yong Yao," was the daughter of Fu Heng, a university scholar, and belonged to the Yellow Banner Fucha clan, and the door was naturally impeccable. The twelfth son of the Emperor, Yongxuan Fujin, was the daughter of a Certain Taiji of Mongolia, surnamed Borjigit, and the seventeenth son of the Emperor, Yongxuan, was the daughter of General Arigun, niuhulu, who belonged to the Niuhulu clan of the Yellow Banner Hongyi Principality. These princes Fujin, except for the twelve brothers Yong Xuan, are slightly worse, Yong Xuan and Yong Xuan are both top giants.
In contrast, the Yongyan Concubine Fujin Hitara clan (Empress Xiaoshurui) is slightly inferior, after all, the Hitara clan has a coat label on it.
Sometimes, ministers would guess the crown prince through the marriage of the crown prince, and it was obvious that the Yongyan concubine Fu Jin Hitara's family lineage was not the best.
However, Yong Yan was very happy about his father's marriage, at that time, the Hitara clan had long been different from the past, detached from the identity of the wrapper, and located in the Three Banners, and the university scholar Laibao was also a very important minister of Qianlong, so Yong Yan was very fond of the Hitara clan and had three children with her, including Mianning, the second son born in Qianlong in the forty-seventh year.
As Yong Yan had predicted, Qianlong's ultimate chosen heir was him, the Jiaqing Emperor. After Jiaqing succeeded to the throne, the Hitara clan entered the middle palace as a concubine Fujin, becoming the only woman in the Qing Dynasty to ascend to the throne with the status of a coat. At that time, the Hitara clan could be said to have unlimited scenery, however, it was unexpected that only one year later, the Hitara clan died in the harem of the Qing Dynasty at the age of 38.
Although under the instructions of Emperor Qianlong of taishang, the noble concubine Niu Hulu succeeded to the Middle Palace as Empress Xiaoherui. However, in terms of choosing an heir, Jiaqing finally finalized Mianning, the eldest son of the original Xi Tara clan, and Mianning was the Daoguang Emperor. As a result, Empress Xiaoshurui became the only original empress of the Qing Dynasty who gave birth to a son of heaven.
References: Draft History of the Qing Dynasty, Records of Emperor Gaozong of the Qing Dynasty, Four Genealogies of the Qing Imperial Family