How many times in Chinese history have there been major migrations of people that changed the political landscape of China at that time?

Historical population migration in my country 1. The "Yongjia Rebellion" period occurred during the Yongjia period of the Western Jin Dynasty. The decadent rulers brutally exploited and oppressed the people of all ethnic groups, thus displacing the majority of people in the Yellow River Basin and being forced large-scale migration to the Yangtze-Huaihe River Basin (mainly flowing into Jiangsu, Anhui, Hubei, Sichuan and other places). This time, about 900,000 people migrated southward, which changed the pattern of population distribution that had been more in the north and less in the south since the Qin and Han Dynasties. The population in the south increased rapidly, which promoted the rapid economic development of the south. This was the shift of China's population distribution center to the Yangtze River Basin. A landmark event. 2. The "Anshi Rebellion" occurred in the Tang Dynasty. About 1 million people moved south, which fundamentally changed the pattern of China's population distribution centered on the Yellow River Basin. For the first time, the population distribution ratio between the north and the south of our country reached a balance. 3. The "Jingkang Rebellion" occurred in the Northern Song Dynasty. In 1125, the Jin Dynasty destroyed the Liao Dynasty and began to go south to attack the Northern Song Dynasty. The Yellow River Basin became 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, and Hubei. , Sichuan, this was the largest stage of population migration in the late Northern Song Dynasty. 4. "Jin Wan Yan Liang" period In 1161, the Jin Dynasty tore up the contract with the Song Dynasty and invaded the south on a large scale. The Huaihe River Basin became the main battlefield, forcing residents in the Huaihe River Basin to move south to the Yangtze River Basin, mainly to Zhejiang, Jiangsu, Hunan, Jiangxi and other places. 5. During the "Mongol Invasion to the South" period, after Kublai Khan ascended the throne, he dispatched a large number of Mongolian soldiers to invade the south in 1273 and launched a war to eliminate the Southern Song Dynasty. The main battlefields were in the middle and lower reaches of the Yangtze River. In order to avoid the war, local residents fled to the Pearl River Basin in large numbers. Migration, mainly to Guangdong, Guangxi, Fujian and other places. 6. The "Going to the West and Entering the Guandong" Period In the late 19th century, in old China, after the invasion of Russian and Japanese imperialists, the two countries competed to expand their power in the Northeast, built railways, and plundered resources, which required a large number of laborers, forcing North China to go bankrupt and farmers to move to the Northeast. In particular, Shandong and Hebei provinces had the largest number of farmers. From 1923 to 1930, 3 million people immigrated to the Northeast, and in 1937, the number reached 700,000 in one year. In addition, Gansu, Qinghai, Xinjiang and other places in the northwest region also have many farmers from Henan, Shaanxi and other provinces. 7. During the "Southeast Coast to Southeast Asia" period, after European and American capitalism invaded Southeast Asia, in order to plunder Southeast Asian resources, they recruited bankrupt Chinese farmers as labor resources for colonial development and sold Chinese laborers, causing the population of Southeast Asia to surge. The plains of the middle and lower reaches of the Yellow River are the birthplace of the Chinese nation. Since the Qin and Han Dynasties, my country's population has spread from the middle and lower reaches of the Yellow River plains to the surrounding areas, focusing on the Yangtze River Basin and the Pearl River Basin in the south. The great population migration caused by the "An-Shi Rebellion" fundamentally changed the geographical distribution pattern of China's population, causing the population in the south to exceed the population in the north for the first time, and the center of China's population distribution moved from the Yellow River Basin to the Yangtze River Basin for the first time. The most direct causes of population migration in our country's history are immigration, war and natural disasters. For example, in the history of our country, every time a war or famine occurs, it will cause a large-scale population migration.