When Emperor Chongzhen of the Ming Dynasty ascended the throne, he inherited a mess. Emperor Chongzhen is not a promising king. In the Ming Dynasty, in the midst of internal troubles and foreign invasion, he hanged himself in Jingshan Park. But the real Ming regime lasted for more than ten years and even succeeded three emperors.
After Beijing was breached by Li Zicheng, Wu Sangui opened Shanhaiguan again, surrendered to Dourgen, and led the Qing soldiers into the customs. At this time, the land of the Central Plains was in anarchy, either the peasant rebels or the Qing army. Anyway, the Ming Dynasty had no influence.
However, in Nanjing, Zhu Youyong, the cousin of Emperor Chongzhen, with the support of the Ming dynasty's elders and generals, ascended the throne and proclaimed himself emperor, and inherited the orthodoxy of the Ming dynasty, which is indisputable. First of all, since the establishment of the Ming dynasty, there have been administrative settings in the north and south. Secondly, according to Ming Zuxun, the emperor has a son and no son to pass on to his brother. It is in accordance with Daming's legal system and the inheritance of brothers and sisters that the establishment of Nanming regime is reasonable and legal.
Then, since the establishment of Nanming regime not only followed the legal system, but also conformed to the etiquette system, why didn't it be recognized by later historians? I think it was the Qing dynasty that discredited the Ming dynasty, which can also be said to be the need of Manchu politics at that time.
After the Qing Dynasty entered the customs, Li Zicheng was driven out of Beijing. Dourgen had a political vision and immediately moved the administrative center of the Qing Dynasty from Shengjing in Liaodong to Beijing, which was equivalent to taking over the dishes of the Ming Dynasty. But at this time, Nanjing has established the Nanming regime. From the perspective of legal system and etiquette, the whole world still belongs to the Ming Dynasty, and the political slogan of the Qing Dynasty's entry into the customs was revenge for Emperor Chongzhen.
This is embarrassing. Now I have come to avenge Emperor Chongzhen, and Li Zicheng is dead. The heir of the Ming dynasty has ascended the throne in Nanjing and inherited the great unity. Is it necessary for Manchu to return to the customs? Dourgen was embarrassed, mainly afraid to face it.
The only way is to announce the death of Emperor Chongzhen to confirm the demise of the Ming Dynasty, and the occupation of Beijing as the capital of the dynasty further confirmed the demise of the dynasty, giving the Qing Dynasty enough excuses to stay and take over the Ming Dynasty.
After Shunzhi proclaimed himself emperor in Beijing, Regent Dourgen did nothing else. One is to improve the rule of the Qing dynasty, and the other is to eliminate the small dynasty of Nanming. Only the demise of Nanming can truly replace the Ming Dynasty, and the Qing Dynasty is the powerful dynasty that unified the whole country.
Therefore, from the historical truth, the Nanming regime was a part of the Ming Dynasty, but because of special political factors, it was not recorded in the history of the Ming Dynasty and was not mentioned by later historians.