Why do Henan, Shandong, Anhui and Jiangsu all speak similar dialects?

There are many dialects in China, and each dialect is segmented. For example, Shangqiu in Henan uses "Zhongyuan Mandarin-Fu Shang Pian-Shangqiu Dialect", and the pronunciation of each dialect may be different, so the tone in some places is similar to that of Henan dialect.

During the period of Wu Zetian in the Tang Dynasty, the capital was Luoyang, Henan Province, which led to a tone similar to Henan dialect in most parts of the north. If we don't divide dialects into smaller ones, Anhui will not use Huizhou, but Central Plains Mandarin. Moreover, Anhui belongs to the dividing line between the north and the south of China, so it is hard to say whether Anhui people are southerners or northerners. People in northern Anhui can be called northerners and people in southern Anhui can be called southerners. Anhui belongs to a mixed land of north and south, with both southern dialects and northern dialects.

Jiangsu spans the Yangtze River and Huaihe River, with obvious differences in regional culture and dialect culture. Jiangsu Province is divided into three dialect areas, namely Jianghuai Mandarin Area, Wuyu Area and Zhongyuan Mandarin Area. Jianghuai Mandarin is divided into Yanghuai, Nanjing and Tongtai. Wu dialect is divided into Taihu Lake piece and Xuanzhou piece, and Taihu Lake piece is subdivided into Su Hu Family piece and Piling piece. Central Plains Mandarin is divided into Xuzhou and Ganyu.

Yangzhou, Taizhou, Nantong, Huai 'an, Yancheng, Nanjing, Zhenjiang and Lianyungang all have dialects belonging to Jianghuai Mandarin.

In China, Jianghuai Mandarin is distributed in Jiangsu, Anhui, Hubei, southern Henan and parts of Jiangxi. The population of Jianghuai Mandarin is about 70 million, mainly distributed between Jianghuai in Jiangsu and Anhui provinces.

Jianghuai Mandarin is divided into Tongtai film, Hong Chao film and Huangxiao film from east to west, among which Hong Chao film accounts for the vast majority. Nanjing dialect used to be the representative pronunciation of Jianghuai Mandarin, but now Yangzhou dialect is generally regarded as the representative pronunciation of Jianghuai Mandarin. Jianghuai Mandarin retains the extinct "Rusheng" in other Mandarin dialects, which is an ancient Chinese dialect.