The Great Wall was built in the Zhou Dynasty.

King Zhou You's beacon-fire play on the princes is the earliest allusion to the Great Wall.

As early as the Spring and Autumn Period in the 7th century BC, the Chu State was the first to build the "Chu Fang City" to defend against invasion by other countries, which opened the curtain on the construction of the Great Wall recorded in Chinese history.

During the Warring States Period, Qi, Wei, Zhao, Qin, Yan, Zhongshan and other countries also successively built the "Great Wall for mutual defense between princes".

Among them, the three kingdoms of Qin, Zhao, and Yan were adjacent to the Xiongnu, a powerful nomadic people in the north. While building the Great Wall for mutual defense between princes, they also built the "Great Wall to Reject Hu" in the north.

After that, almost every king in the past dynasties strengthened and repaired the Great Wall.

After the unification of Qin, the Great Wall that separated various countries was abandoned, and the Great Walls on the northern borders of Qin, Zhao, and Yan were connected, expanded and repaired, and for the first time a Great Wall was formed that stretched from Lintao in the west to Liaodong in the east for more than 10,000 miles.

The Great Wall emerged from this.

According to records, Qin Shihuang used nearly one million laborers to build the Great Wall, accounting for one-twentieth of the country's total population at that time.

The Han Dynasty continued to build the Great Wall to resist the invasion of the Huns from the north.

From Emperor Wen of the Han Dynasty to Emperor Xuan of the Han Dynasty, a Great Wall was built starting from Dayuan Second Division City in the west to the north bank of the Yalu River in the east, with a total length of nearly 10,000 kilometers.

There was no machinery at that time, and all labor was done by manpower. The working environment was also very difficult in the high mountains, steep cliffs, and deep ravines.

The Great Wall was first built during the Spring and Autumn Period and the Warring States Period, with a history of more than 2,000 years. The Great Wall referred to today mostly refers to the Great Wall built in the dynasty.

In addition to the "Outer" Great Wall, the Ming Dynasty also built the "Inner" Great Wall and the "Inner Three Passes" Great Wall.

The "Inner Border" Great Wall is based on the Northern Qi Dynasty. It starts from the west of Pianguan Pass at the junction of Inner Mongolia and Shanxi. It goes eastward through Yanmen Pass and Pingxing Pass and enters Hebei Province. Then it goes northeast, passing through Yuanyuan, Fangshan, and Changping Counties, and reaches Juyong Pass.

, and then from north to east, to the Sihai Pass in Huairou, connecting with the "outer" Great Wall, with Zijin Pass as the center, running roughly in a north-south direction.

The "Inner Three Passes" Great Wall runs parallel to the "Inner Border" Great Wall in many places, and in some places the two cities are only tens of miles apart.

In addition, a large number of "heavy cities" were also built.

There are 24 "important cities" in the Yanmenguan area.

According to historical documents, more than 20 vassal states and feudal dynasties built the Great Wall. If the Great Walls built in various eras are added up, the length is more than 100,000 miles.

Among them, the length of the Great Wall built in the Qin, Han and Ming dynasties all exceeded 10,000 miles.

China's Xinjiang, Gansu, Ningxia, Shaanxi, Inner Mongolia, Shanxi, Hebei, Beijing, Tianjin, Liaoning, Jilin, Heilongjiang, Henan, Shandong, Hubei, Hunan and other provinces, cities and autonomous regions all have the remains of the ancient Great Wall and beacon towers.

[3] The Great Wall in northern China began during the Warring States Period, between the three kingdoms of Qin, Zhao and Yan.

Why Qin Zhaoyan wanted to build the Great Wall in the north starts with the situation during the Warring States Period.

The Warring States Period was a period of transition from slave society to feudal society in the middle and lower reaches of the Yellow River and Yangtze River in my country. The exchange and integration of the Xia culture and the cultures of Qin, Chu, Wu, and Yue led to an increasingly strong trend of unification.

After the seven kingdoms of Wei, Zhao, Han, Chu, Qi, Qin, and Yan, which were undergoing feudal reforms at that time, became strong, they engaged in annexation wars and sought to unify the middle and lower reaches of the Yellow River and Yangtze River by force.

At this time, the ethnic minorities in the grasslands of northern Shaanxi, northern Shanxi, northern Hebei and Inner Mongolia, mainly the Xiongnu, also became stronger and continued to plunder the northern borders of Qin, Zhao and Yan.

There are Yiqu and the Xiongnu in the north of the Qin State; Linhu and Loufan are in the northwest of the Zhao State, and there are Huju and the Xiongnu in the north; and Donghu is on the northern border of the Yan State.

Since the middle of the Warring States Period, they have continued to plunder the northern areas of Qin, Zhao, and Yan.

Because they are good at riding and shooting, and good at field battles, they adopt sudden attacks, come and go erratically, and are elusive, showing strong combat effectiveness.

However, the combat troops of Qin, Zhao, and Yan in the middle period of the Warring States Period were mainly infantry and chariots. They wore loose clothes and long sleeves. They moved slowly and could travel 30 to 50 miles a day. Naturally, they could not stop the attacks and plunders of the Xiongnu and Donghu.

This not only severely threatened the lives and property of the people in the northern part of the three countries and severely damaged production, but also greatly affected the unification cause of the three countries.

In response to this passive situation, the three countries successively carried out military reform and built the Great Wall in the north.

The Qin State began to implement reforms since Shang Yang, promoting a prosperous country and a strong army.

The army gradually changed into infantry and cavalry, and was rewarded and promoted based on military merit. Therefore, the army's combat effectiveness increased and it became invincible.

In the sixth and tenth years of King Huiwen's reign (332 BC), he defeated the Wei State and seized Wei Xihe County (now the Luohe River Basin in Shaanxi Province) and Shangjun (now northeastern Shaanxi Province).

In order to prevent the Huns from raiding the south, King Zhao ordered the construction of the Great Wall at the northern borders of Longxi, Beidi and Shangjun and stationed troops there.

The Great Wall at Night In the 19th year of King Wuling (307 BC), the State of Zhao began to reform its military system and practice riding and shooting in Hu uniforms.

Since then, the military strength has become stronger.

In the 20th year, King Wu Ling marched westward to the Linhu area and reached Yuzhong. King Linhu offered his horse to surrender and then returned with his troops.

In the twenty-sixth year (300 BC), they broke through Zhongshan and conquered the territory as far north as Yan and Dai (today's northwestern Shanxi), and then expanded northwest to Yunzhong and Jiuyuan (today's Horlinger County in Inner Mongolia to the Wuga River area).

Therefore, the Great Wall was ordered to be built from Dai to the Yin Mountains (today's Daqingshan and Urad Mountains in Inner Mongolia) to the west to the Dahe River (today's Wuga River in Inner Mongolia), and to establish Dai, Yanmen, and Yunzhong counties to prevent the Xiongnu from going south to plunder.

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In order to specialize in the northwest, he gave way to his son Huiwen Wang He the following year, calling himself Lord Father.