What kind of migration history has Hakkas experienced?

Since the "An Shi Rebellion" in the Tang Dynasty, the national situation has turned from prosperity to decline, and the situation of separatist regions has occurred from time to time. Coupled with the famine in the central plains for years, the government exploited and exploited, and the people were in dire straits. Many fireworks in urban and rural areas have been broken, and it is a depression. Soon, the peasant uprising led by Wang Xianzhi and Huang Chao broke out. The insurgents crossed the Central Plains and moved to Yu Sheng in the north and south. These places are the areas where the Han people moved south for the first time. Only Gannan, southwestern Fujian and northeastern Guangdong are the "promised land" affected by the war, so most of the Hakka ancestors in these provinces went back to the Ganjiang River from Jiangzhou and settled in the triangle of Gannan, western Fujian and northeastern Guangdong today. According to the records of Hakka genealogy, most immigrants in this period took refuge in Shibidong, Ninghua, Fujian. This is the second large-scale migration in the history of Han nationality in Central Plains. This southward migration lasted for more than 90 years and lasted until the Five Dynasties after the Tang Dynasty.