How many states were there in the Tang Dynasty during the Tang Dynasty and Wu Zetian's reign? Where is it now?

There were 10 counties and 358 states in the Tang Dynasty, as follows:

Inside Shanhaiguan Pass: It is roughly equivalent to north-central Shaanxi, Longdong of Gansu and Hetao of Inner Mongolia.

Henan: It is roughly equivalent to the area south of the Yellow River in Henan and Shandong provinces and north of the Huaihe River in Henan, Jiangsu and Anhui provinces.

Hedong: It is roughly equivalent to the area between Shanxi Province and the Great Wall in the northwest of Hebei Province.

Hebei: It is roughly equivalent to the south of the Great Wall in Hebei and most areas north of the Yellow River in Henan and Shandong provinces.

Shannan: It is roughly equivalent to today's eastern Sichuan, southwestern Shaanxi, southern Gansu, southwestern Henan and western Hubei.

Longyou: It is roughly equivalent to the area west of Longshan and Liupanshan in Gansu Province, east of Qinghai Lake in Qinghai Province and east of Xinjiang.

Huainan: It is roughly equivalent to the area south of Huaishui in Anhui, Jiangsu and Henan provinces and north of the Yangtze River in eastern Hubei.

Jiangnan: roughly equivalent to Zhejiang, Fujian, Jiangxi and Hunan provinces, Jiangnan in Jiangsu and Anhui, a part of Jiangnan in Hubei and Sichuan, and the northeast of Guizhou.

Jian Nan: It is roughly equivalent to the present central Sichuan and northern Yunnan.

Lingnan: roughly equivalent to Guangdong, Guangxi and northeastern Vietnam.

Extended data:

At the end of Sui Dynasty, Tang Gaozu changed the county system to the state system, and Tang Xuanzong changed the state system to the county system. After his son Tang Suzong succeeded to the throne, the county was changed to a state, so the state dominated the Tang Dynasty. In the Northern Song Dynasty, Ouyang Xiu's Book of the New Tang Dynasty also described the county seat in the Xuanzong period of the Tang Dynasty, while the Book of the Old Tang Dynasty was organized by the state.

However, the concept of state is fundamentally different from that of Han, Wei and Jin Dynasties. Compared with the situation of more than 0/00 counties under the jurisdiction of the state in the late Eastern Han Dynasty, the scope of the state in the Tang Dynasty has been greatly reduced to several or even more counties.

In addition, during the Han and Jin Dynasties, many counties under the jurisdiction of the original county followed the original name of the country, but the original name gradually became unknown. For example, Pengcheng became Xuzhou, Xindu became Jizhou, Changyi became Yanzhou, and Jiangling became Jingzhou. At the same time, since the Qin and Han Dynasties, and even during the Spring and Autumn Period and the Warring States Period, many place names, such as Langya, Hongnong and Shangdang, have no longer been used in history.

References:

Baidu Encyclopedia-Administrative Divisions of Tang Dynasty