What is the reason why the center of gravity of China's traditional culture moves south?

This is mainly caused by many historical events:

1, Three Kingdoms Period: Wu Dongding established Jianye (Nanjing), vigorously developed the southern economy, which was greatly strengthened and began to have an economic foundation for cultural development;

2. Eastern Jin Dynasty: The north was divided by 16 ethnic minority countries (so-called "five wild flowers"), and a large part of the original literati in the north followed the Eastern Jin Dynasty to inform the class to move south. This is the first time that the culture moved south. Since then, the cultures of the south and the north have developed in two lines.

3. Sui and Tang Dynasties: the North and South cultures merged and the cultural peak appeared. At this time, the national cultural development was balanced, but the main body returned to the Central Plains;

4. Song Dynasty: Song Dynasty was the dynasty with the highest cultural development in China's history, but it was also one of the dynasties most bullied by foreign enemies. With the high development of culture and art, it is constantly compressed by the northern Khitan and the western Xixia, which leads to the shift of political, cultural and economic center of gravity to the south. When the rulers just moved south, the whole Song Dynasty was forced to move south, and finally only the southern territory could be preserved, so the whole center of gravity moved south.