Why did the Tang Dynasty advocate not building the Great Wall at the beginning of its founding?
One of the reasons is related to the three very eye-catching cities on the northern border of the Tang Empire, namely the three "surrendered cities" in the west, middle and east.
Speaking of the grasslands in the north of the Tang Dynasty, they were successively controlled by the Turks and Hui, which had hundreds of thousands of troops.
This will undoubtedly put a huge pressure on the Tang Dynasty in the south.
Since Emperor Taizong of Tang, he has deliberately taken advantage of the loose internal and decentralized ruling power of the steppe khanate, and gradually made the northern ethnic groups submit to the Tang Dynasty in the south.
At the beginning of the second year of Emperor Jinglong of The Tang Dynasty, that is, in 708 AD, the Tang Dynasty simultaneously built these three surrendered cities as powerful fortresses to control the steppe peoples.
In fact, these three cities do serve as a very powerful deterrent:
"Shuofang did not retaliate and plundered, reducing the number of soldiers in the town by tens of thousands."
The steppe people no longer dared to go south to the Shuofang homeland to plunder, so the local people were able to reduce their troops by tens of thousands.
Among them, the confirmed ruins of the zhongzhong descending city have a circumference of 1500 meters and a side length of about 375 meters.
It can be said that the size of these three cities should not be much different, and they are very similar to fortress towns.
Speaking of these three surrendered cities, the most prosperous should be the Western Descending City located in the middle banner of Urart.
In the fifteenth year of Emperor Xuanzong's reign (727), the Turkic Khan sent an envoy to Zhi'an to report to Chang'an that "Tubo wanted to join forces with his troops to attack the Tang Dynasty", which was deeply appreciated by Tang Xuanzong.
In order to repay the khan's kindness, Tang Xuanzong allowed the people of the steppe to trade with the Tang in the western city according to the old practice.
In order to show its sincerity, the Tang Dynasty transported "hundreds of thousands of horses" of silk every year, and as for the city of the Western Surrender, "it was left behind".
All kinds of livestock on the grasslands entered Datang as exchange materials.
It can be said that both sides took what they needed, and for a long time maintained a peaceful situation of "Huayi is comfortable and the armored soldiers rest" are maintained.
During the tang xuanzong period, the Tang dynasty was almost attacked on all sides, and Tubo, Nanzhao, and Bohai were not fuel-saving lamps.
Since the western city was used as a trading point with the steppe tribes, the Tang Dynasty purchased a large number of good horses with "Jin Shuai", placed them in Hedong, Shuofang and Longyou areas to graze, and mated with Tang Dynasty horses, so that the excellent genes of grassland horses made the Tang army war horses "stronger", which was of great benefit in the war.
Later, in addition to the steppe peoples, the Tiele in the north of the desert, as well as the Sogdians in the northeast, the Jing people, and so on also came to the western city of surrender:
"In December of the sixth year of Tianbao, Jiu surnamed, Jiankun, and Murong Wei offered sixty horses, and Yu Xi was sent to the city to accept them."
At the beginning, the scale of horses bought and sold in XishouCheng was about three or four thousand horses per year, but then it gradually soared to fourteen thousand, worth 500,000 silk, which was naturally the result of the prosperity of trade in Xishou City and the efforts of merchants from all over the world to increase the scale of trade.
It is worth mentioning that at the beginning of the founding of the Tang Dynasty, it advocated not building the Great Wall, which is rare in Chinese history.
This is related to the military strength of the early Tang Dynasty, and in the middle and late period, it is also related to the surrendered city, because compared with the Great Wall, the scale of the three descended cities is much smaller, and the manpower, material resources, and financial resources are much less, and it also plays a positive role in the defense of the border stalemate.