Why do Hakkas move south?

In the first migration, the Han nationality who took refuge in the two branches of the Central Plains spread southward, reaching the south-central part of Jiangxi as far as possible, while the most recent one was still stranded in the Ruhan River in Huai Ying. During the Sui and Tang Dynasties, they slept, rested, tired and gradually settled in the Soviet Union, and gradually lived a relatively comfortable life. Therefore, from the Eastern Jin Dynasty to the Sui and Tang Dynasties, it can be said that Hakka ancestors migrated from north to south in the first period. Second Migration: In order to save their lives, they entered Poyang Lake Plain, traced Ganjiang River to Gannan, turned eastward, and passed Shicheng to southwest Fujian, such as Ninghua, while the Eastern Jin immigrants who stayed in Huai Ying and Rusanshui did not migrate, and even crossed the river south to Zhang Ting and Wang Chao brothers. Some of these immigrants are the ancestors of Hakkas. In this migration, the farthest reaches Hui, Jia, Shao and other places, and the most recent reaches the third migration, such as Changting, Ninghua, Shanghang, Yongding and other places in Fujian. Due to the invasion of Nandu and Yuan people, Hakka ancestors wandered around and flowed into eastern Guangdong and northern Guangdong, or because they were dissatisfied with the diligent king, they followed the emperor's command and became the land of Hakka, and the recent ones were all over eastern Jiangxi and southern Jiangxi. Later, Song Taizu unified China, and the Han people who went south began to feel a little comfortable. The fourth migration, on the one hand, is based on the expansion of internal population, on the other hand, is based on the influence of Manchu tribes in China. The coastal areas of Sichuan and Guangdong, as well as Taiwan Province Province, were either abandoned due to military disasters, declined due to relocation, or sparsely populated, forcing farmers to move towards the fifth period of Hakka immigration movement. During the Tongzhi period of Qing Dynasty, influenced by the Guangdong West Road incident and the Taiping Heavenly Kingdom Movement, some Hakkas moved to Guangdong South Road, Hainan Island, Taiwan Province Province, Hong Kong, Macau, Nanyang Islands, and even as far away as Europe and America. This is the fifth great migration and a worldwide migration after the failure of Taiping Army.