How many important migration waves have occurred in the history of our country?

Historically, China's population migration was 1. The period of "Yongjia mourning" occurred in Yongjia period of the Western Jin Dynasty. The corrupt rulers brutally exploited and oppressed people of all ethnic groups, thus making people in the Yellow River basin displaced and forced to move to Jianghuai basin on a large scale (mainly into Jiangsu, Anhui, Hubei, Sichuan and other places). The population moving south is about 900,000, which has changed the pattern of large population in the north and small population in the south since Qin and Han Dynasties. The population in the south has increased rapidly, which has promoted the rapid economic development in the south. This is a landmark event that the population distribution center of China has shifted to the Yangtze River basin. 2. The "An Shi Rebellion" occurred in the Tang Dynasty, and about 6,543,800 people moved southward, which fundamentally changed the pattern that China's population distribution was concentrated in the Yellow River basin, and the proportion of population distribution between the north and the south of China reached a balance for the first time. 3. The "Jingkang Rebellion" happened in the Northern Song Dynasty. 1 125, Jin destroyed Liao and began to attack the northern song dynasty in the south. The Yellow River basin has become the main battlefield. Every major war caused a large number of residents in the Yellow River basin to migrate to the Yangtze River basin, mainly to Zhejiang, Jiangsu, Hubei and Sichuan, which was the largest stage of population migration in the late Northern Song Dynasty. 4. During the "Jin Yan" period, Jin tore up the contract with the Song Dynasty and invaded the south on a large scale, forcing the residents of Huaihe River basin to move south to the Yangtze River basin, mainly to Zhejiang, Jiangsu, Hunan, Jiangxi and other places. 5. During the period of "Mongolian soldiers invading south", Kublai Khan and others arrived at the position of the khanate. 1273, a large number of Mongolian soldiers invaded south and launched a war to destroy the Southern Song Dynasty. The main battlefield is in the middle and lower reaches of the Yangtze River, and a large number of local residents have moved to the Pearl River basin to escape the war, mainly in Guangdong, Guangxi and Fujian.