How did the population migrate to the south in the ancient history of China?

The population of the north migrated to the south, and the population of the south gradually increased.

In the Western Han Dynasty and the Tang Dynasty, the population (households) and proportion between the north and the south are as shown in the figure below:

China's three southward movements;

1. The first large-scale migration wave in China's ancient history was from the late Eastern Han Dynasty to the Wei, Jin, Southern and Northern Dynasties. Due to the scuffle between the northern and central plains minority regimes, a large number of people moved south, bringing sufficient labor and advanced production technology to the south, and the Jiangnan area has been greatly developed. This laid the foundation for the gradual shift of China's economic center of gravity to the south.

2. The "An Shi Rebellion" in the 14th year of Tang Tianbao (755) triggered the second large-scale population migration in the ancient history of China. A large number of people moved to the south, and the south was further developed, especially in the Jianghuai and Taihu areas, which became a new wealth area in China. In the Five Dynasties, the economy of the south began to gradually surpass that of the north.

3. The third large-scale population migration in the ancient history of China was from the "difficulty of Jingkang" at the end of the Northern Song Dynasty to the end of the Southern Song Dynasty. During the Song Dynasty, with the further southward migration of the northern people, the southern economy has surpassed the northern economy in China, and the process of the southward migration of the ancient economic center of China was finally completed.