In ancient China, the increase in population has not been very large, basically within one hundred million, and the peacetime may reach tens of millions, while the war and chaos years may have dropped to about a few million. By the end of the Ming Dynasty, due to frequent wars, both Li Zicheng and Zhang Xianzhong's peasant revolts, as well as the Ming Dynasty's battles with the Qing army, resulting in a sharp decline in population. By the time of the fall of the Ming Dynasty in 1644, the population of the country was about 50 million, but when the Qing army entered the customs and established the Qing Dynasty, after the Shunzhi, Kangxi, Qianlong, and Yongzheng dynasties, the population grew sharply to 400 million.
In this short period of more than 10 years, China's population has almost increased tenfold, of which the population growth was the largest in the six years of Qianlong's reign, the total population of the country has reached 290 million, close to 300 million, and in peacetime more than 400 million, about 41.3 million. Why, then, did the Qing Dynasty grow its population much more than it did in thousands of years in less than 30 years?
I think there are several reasons, the first of which is the expansion of the territory, which must lead to population growth. The largest territory of the Ming Dynasty was the Yongle period, with a total area of about 12.33 million square kilometers, while the largest territory of the Qing Dynasty was 13.19 million square kilometers, south to Zengmu Dark Sand, northeast to Daxing'anling and Sakhalin Island, north to Siberia, northwest to Onion Ridge, east to Taiwan, Penghu Islands, the Qing Dynasty's huge territorial territory, which is one of the foundations of population growth.
Second, during the reign of the Qing Dynasty, there were not many wars against foreign troops, basically in a peaceful era, the people could rest and recuperate, actively procreate, and the population grew rapidly.
The third is the improvement of agricultural technology. During the Qing Dynasty, high-yielding crops such as potatoes, sweet potatoes, and corn from South America and other places were introduced to China, and these crops were extremely suitable for farming in China's mountainous areas. These alien species have replaced the original low-yielding xiangzhi and other crops in ancient China at a very fast speed, and the yield of crops has increased, which is an important material guarantee for the survival of the birth population. Moreover, in the Kangqian and other dynasties, many land tax policies were introduced, these policies increased the area of cultivated land, increased grain production, that is, the Qing Dynasty broke through the ancient population ceiling, and maintained a long period of rapid population growth, the last point is that the Medical Technology of the Qing Dynasty has also been improved compared with the previous dynasty, and some epidemic diseases that were originally helpless can be cured during the Qing Dynasty. As the birth rate rises, the mortality rate continues to decrease, which makes people live longer and the population increases.
In general, population growth has several factors, a stable social environment, adequate food and policies pursued by the rulers, as well as medical technology. And these factors were all possessed by the Qing Dynasty, so the population of the Qing Dynasty would show explosive growth.