Are the Sixteen Prefectures of Yanyun south of the Great Wall or north of the Great Wall?

To the south, it was probably most of what is now north of Henan. In today's Beijing, Tianjin, and sixteen prefectures in northern Shanxi and Hebei.

From Bohai Bay in the east to Chenjia Valley in the west of Yanmen Pass in the west, the terrain is very dangerous, and it is an important defense area for the Central Plains region to defend against the northern nomads. During the Five Dynasties, Shi Jingjiao dedicated 16 weeks to gain the support of the Liao State, which led to a large retreat of the later Zhou Dynasty and the Northern Song Dynasty's defense line, which was also one of the important reasons for the demise of the Northern Song Dynasty in the later period.

Here's a list of 16 states.

Youzhou (present-day Beijing), Shunzhou (present-day Shunyi, Beijing), Ruzhou (present-day Yanqing, Beijing), Danzhou (present-day Miyun, Beijing), Jizhou (present-day Jinjixian), Zhuozhou (present-day Zhuozhou, Hebei), Yingzhou (present-day Hejian, Hebei), Mozhou (present-day Renqiubei, Hebei), Xinzhou (present-day Zhuolu, Hebei), Yanzhou (present-day Huailai, Hebei), Wuzhou (present-day Xuanhua, Hebei), Ulzhou (present-day Weixian, Hebei), Yingzhou (present-day Yingxian, Shanxi), Huanzhou (present-day Shuozhou, Shanxi), Shuozhou (present-day Shuozhou, Shanxi), and Yunzhou (present-day Datong, Shanxi).

Copying is shameful, plagiarism is even worse!!

Sixteen states of Youyun.

Youzhou (present-day Beijing), Shunzhou (present-day Shunyi, Beijing), Ruzhou (present-day Yanqing, Beijing), Danzhou (present-day Miyun, Beijing), Jizhou (present-day Jinjixian), Zhuozhou (present-day Zhuozhou, Hebei), Yingzhou (present-day Hejian, Hebei), Mozhou (present-day Renqiubei, Hebei), Xinzhou (present-day Zhuolu, Hebei), Yanzhou (present-day Huailai, Hebei), Wuzhou (present-day Xuanhua, Hebei), Ulzhou (present-day Weixian, Hebei), Yingzhou (present-day Yingxian, Shanxi), Huanzhou (present-day Shuozhou, Shanxi), Shuozhou (present-day Shuozhou, Shanxi), and Yunzhou (present-day Datong, Shanxi).

The Sixteen Prefectures of Youyun were occupied by the Liao State during the Five Dynasties, and the Great Wall of the county was built during the Ming Dynasty, which was not available at that time. Some of them, such as Huanzhou (now Shuozhou, Shanxi), Shuozhou (now Shuozhou, Shanxi), and Yunzhou (now Datong, Shanxi) were later the Great Wall Passes, and most of the rest were south of the Great Wall of the Ming Dynasty.

The sixteen prefectures of Yanyun were: Youzhou (now Beijing), Shunzhou (now Shunyi, Beijing), Ruzhou (now Yanqing, Beijing), Danzhou (now Miyun, Beijing), Jizhou (now Jinjixian), Zhuozhou (now Zhuozhou, Hebei), and Yingzhou (now Hejian, Hebei).

Mozhou (present-day Renqiubei, Hebei), Xinzhou (present-day Zhuolu, Hebei), Yanzhou (present-day Huailai, Hebei), Wuzhou (present-day Xuanhua, Hebei), Ulzhou (present-day Weixian, Hebei), Yingzhou (present-day Yingxian, Shanxi), Huanzhou (present-day Shuozhou, Shanxi), Shuozhou (present-day Shuozhou, Shanxi), and Yunzhou (present-day Datong, Shanxi).

The seven prefectures of You, Ji, Ying, Mo, Zhuo, Tan and Shun are located in the southeast of the northern branch of the Taihang Mountains, and the remaining nine prefectures are in the northwest of the mountains, and the sixteen prefectures are roughly the large areas of land in present-day Beijing, Tianjin, northern Hebei and northern Shanxi.

The strategic importance of the sixteen states of Yanyun.

Wang Wei's poems are all protected in Yan Ran's Yan Ran Mansion) will be a disaster to Yanyun, and losing Yanyun will be a disaster to the Central Plains. The sixteen states of Yanyun are also known as the "sixteen states of thistle".

You, Ji, Ying, Mo, Zhuo, Tan, Shun seven states are located in the southeast of the north branch of Taihang Mountain, the rest of the Yun, Confucian, Concubine, Wu, Xin, Wei, Ying, Huan, Shuo Kyushu in the northwest of Taihang Mountain, the importance of the sixteen states of Yanyun to the south is like Lingbei Province to the north, the terrain is condescending, easy to defend and difficult to attack, the geostrategic value is huge, the Yuan Dynasty called it the belly.

The sixteen prefectures of Yanyun are the current urban areas of Beijing, Shunyi District of Beijing, Yanqing District of Beijing, Miyun District of Beijing, Jizhou District of Tianjin, Zhuozhou of Hebei, Hejian City of Hebei Province, Renqiu City of Hebei Province, Zhuolu County of Zhangjiakou City of Hebei Province, Huailai County of Zhangjiakou City of Hebei Province, Xuanhua District of Zhangjiakou City of Hebei Province, Wei County of Zhangjiakou City of Hebei Province, Ying County of Shanxi Province, East of Shuozhou City of Shanxi Province, Shuozhou City of Shanxi Province, and Yunzhou District of Datong City of Shanxi Province.

The Sixteen Prefectures of Yanyun, also known as the Sixteen Prefectures of Youyun and the Sixteen Prefectures of Youji, are very important in their geographical location, which is a place where soldiers of all dynasties must fight, and is also a natural barrier against the invasion of nomads.

Sixteen states of Yanyun.

It is the present: Youzhou (now Beijing), Shunzhou (now Shunyi, Beijing), Ruzhou (now Yanqing, Beijing), Danzhou (now Miyun, Beijing), Jizhou.

Today Jinji County.

Zhuozhou (now Zhuozhou, Hebei), Yingzhou (now Hejian, Hebei).

Mozhou (now Renqiu, Hebei.

north), Xinzhou (now Zhuolu, Hebei), Yanzhou (now Huailai, Hebei), Wuzhou (now Xuanhua, Hebei), Ulzhou (now Weixian, Hebei.

Yingzhou (now Yingxian County, Shanxi), Huanzhou (now Shuozhou, Shanxi), Shuozhou (now Shuozhou, Shanxi), Yunzhou (now Datong, Shanxi).