What is the influence and function of ancient immigrants in China?

China's ancient population migration was mainly due to wars, such as the war in the late Eastern Han Dynasty, which led to a large number of people moving south. During the Qin and Han Dynasties, the population of China was mainly concentrated in the Yellow River basin, and the war led to the migration of population to the south and the initial development of the south. During the Wei, Jin, Southern and Northern Dynasties, the ancient population of China moved to the south on a large scale, which fully developed the south and laid the foundation for China's economic migration to the south. By the end of the Tang Dynasty, the population moved to the south again on a large scale, and the massive loss of the population in the north made the agricultural economy decline in an all-round way, and the economic development in the south surpassed that in the north. By the Northern Song Dynasty, the population of the south had surpassed that of the north, and the south had become the economic center of China until now.