Most Han Chines today can trace their origin from southern Shanxi 山西, around Lin Fen 临汾, Hong Tong Village area. In Ming dynasty, due to internal war, most regions in China are short of people while the population of Shanxi, due it location bound by the Taihang mountains and the Huang He river, is booming in southern part of Shanxi. So the Ming emperor asked for a major migration of several millions people to other provinces such as Henan, Shandong, Anhui, Jiangsu, Hubei, Hunan. Subsequently people from these later provinces miigrated to other provinces such as Sichuan, Zhejiang, then to Fujian and Guangdong. Today, there are travel tour for Chinese from mainland and overseas to come back and visit this part of southern Shanxi, it called 寻根问祖. Also noted that Shanxi and neighboring Gansu/Shaanxi is the land where the Huaxia 华夏 tribes come from. The temple to commemorate one of the earliest ruler of Chinese people "Yao" 堯 (2000 BC) is also located in this area.

It seems that these new internal migrations moslty populated provinces to the north of Guangdong and Fujian. So the majority of people from Guangdong and Fujian trace their ancestors to older Han Chinese migration mixing in with the local Yue people, therefore they have their distintive dialects and called themselves people of Tang 唐 dynasty. Are there significant internal Han Chinese migration in 15th-16th from northern areas to Fujian and Guangdong areas?

most of these newer immigrants from the 16th and 17th century are what we know as the Hakkas, who now mostly live in the Meixian county of Guangdong. There are also alot who live in the Taishan - Shenzhen - Hong Kong coastal areas where the cantonese lived... which as a result there was a Punti-Hakka Civil war especially between the Sei Yap Cantonese and the Hakkas. The later immigrants(after the hakkas) i guess got assimilated into the cantonese population since they didn't come in waves like the Hakkas did. 21st Century mass migration of peasants and entrepreneurs from other parts of china coming into guangdong.. choose to live and work in the cities like Shenzhen, Dongguan, Guangzhou, Zhuhai, Jiangmen.