The origin of the name of the Qing Dynasty
The ancestors of the Manchus were originally the Jurchen tribe of the Jin Dynasty, so Nurhaci named the country "Dajin" after unifying the Jurchen tribes. Soon, in order to distinguish it from the Jin Dynasty in history, it was renamed "Later Jin". Many Mongolians, Hans, Koreans, etc. were under his rule, and it was no longer suitable for them to use the "Later Jin" country name. Moreover, due to the influence of history, the Han people had always had a dislike for the Jin people, and the "Later Jin" country name was not suitable for attracting Han people. It was not appropriate, so Huang Taiji changed the name of the country to "Qing" ten years after he succeeded to the throne, that is, the tenth year of Tiancong (1636).
So, why did Huang Taiji use "Qing" as the country's name?
There are two theories. It is said that one year before changing "Houjin" to "Qing", Huang Taiji had abolished the "Jurchen" clan name and changed it to "Manzhou". The pronunciation of "Manzhou" in Manchu is similar to "Manshu". It is originally the name of Buddha, meaning "Emperor of the Qing Dynasty" and the incarnation of Buddha. Therefore, he replaced "Jin" with "Qing", which played a greater role in winning over the hearts of all ethnic groups and further replacing the Ming Dynasty than "Da Jin" or "Later Jin". At the same time, Huang Taiji also created public opinion to overthrow and replace the Ming Dynasty, saying that only the virtuous can rule the world. These words, "Only the virtuous can be called the emperor", "The virtuous will be appointed, and the unvirtuous will be abandoned." became the core of his thinking. And what he meant by "virtue" contained the meaning of "Qing", which coincided with the semantic meaning of "Manzhou", so "Qing" was used as the country's name.
Another theory is just the opposite, which is to sacrifice meaning and seek pronunciation. In Manchu, "Qing" is the homophony of "金", and "Qing" in Chinese is the Manchu word "金". "金" Changing it to "Qing" was to change the Han Dynasty but not the Manchu Dynasty. Its purpose was only to adapt to the needs of attacking the Ming Dynasty and make it easier for the Han people to accept it. People who hold this view cite the Manchu term "Fu Jin" for noble ladies as an example. They say that "Fu Jin" was first called "Fu Jin", then changed to "Fu Jin", and finally "Fu Jin", so "Fu Jin" "Fu" and "Fu", "Jin" and "Jin" have the same pronunciation in Manchu. Therefore, according to Manchu pronunciation, "Qing" and "Jin" also have the same pronunciation. This theory is also evidenced by the Fujinmen's forehead in Shenyang (the old capital of the Qing Dynasty). The Chinese characters on the plaque are "大金", while the Manchu characters are "大清". This plaque was erected during the Tiancong period. At that time, the name had not yet been changed to "Qing", but it was already called "Qing" in Manchu.
The two theories have different reasons, but both believe that changing the country's name to "Qing" was out of political necessity, mainly to win over the Han people and prepare to replace the Ming Dynasty. From this point of view, the first statement should be accepted. This can be supported by the fact that later the rulers of the Qing Dynasty always concealed the names of "Jurchen" and "Dajin".