The role of city walls

Every ancient city has a city wall, which is the flavor of the city. I like to ride slowly around the ancient city wall of Jingzhou and enjoy the leisure of visiting the ancient city!

Building city walls, like many people building walls for their own yards, is mainly for defense and protection. After all, safety comes first. Structurally, the ancient city wall is like this. The outermost is a moat, which surrounds the city wall. We visited the Forbidden City in Beijing. The outside of the Forbidden City is also surrounded by a river, which can be regarded as the moat of Miyagi. There is an old saying: there is a fire at the city gate, which affects the fish in the pool. That is to say, the gate was on fire, and people ran to the moat to draw water to put out the fire. As a result, the moat was drained, there was no water, and all the fish in the river died. There are usually suspension bridges on the moat, which can be put away and put down. When fighting, you can prevent the enemy from rushing directly to the gate. Crossing the suspension bridge is the city wall, and there is a gate under the city wall. Most doors are made of wood. After closing the door, bolt the door with big wood. The wooden pillar of the vertical bolt door is called "planting", and the one of the horizontal bolt door is called "closing". The pillar of the bolt door is thick and heavy, and it will be reinforced with copper hoops several times. It is known to all the people in the country that there are towers on the city walls. Look at Tiananmen Square. There will also be towering enemy towers on both sides of the tower, which is equivalent to a watchtower and can observe the enemies outside the city. At the top and outside of the city wall, there is a continuous uneven and toothed low wall called "crib mouth" or "crib wall". It has a crib on it, and soldiers guarding the city can hide behind it to shoot arrows and watch, and the lower part has ventilation holes to protect the city wall. The inner low wall is called the "female wall", which is lower than the crib mouth and similar to the guardrail to prevent soldiers from falling when coming and going. On the wall of the city wall, sometimes a platform is built, called horse face, which protrudes outward, also for defense. You see, when the enemy attacked the city wall, he attacked the city and guarded it, one side at a time. If you build a horse face, it means that you have an extra side and can attack the enemy from the side. When the enemy attacked the city, the gate was very fragile. Therefore, in order to protect the city gate, many city walls, the so-called urn walls, will be built around the city gate. The wall of the urn wall is connected with the main wall. If the enemy attacks the urn wall and continues to attack the city gate, then the defenders can stand on the top of the main wall and the urn wall and command counterattacks from all directions, and it will be difficult for them to break through the city gate.

After talking about the structure of the wall, let's talk about the material of the wall. The city walls we see now, such as the An City Wall in Xi, the Nanjing City Wall and some towers in Beijing, are all wrapped in bricks, or even made entirely of bricks and stones. In fact, most of the ancient city walls in China were earth walls, or rather, rammed earth walls. It is to pound the soil into pieces, similar to adobe, and then pile it up. During the Southern and Northern Dynasties, the earth wall was covered with a layer of brick, but until the Tang Dynasty, the walls of Chang 'an, the capital city, were rammed earth walls, and Daming Palace in Miyagi was also rammed earth walls. There is a problem with rammed earth walls. Rammed soil is square, which will be very fragile at the corner of the wall, and it is easy to leave defensive loopholes. To make up for it, a corner of the city wall will be built higher and thicker. There is a poem in the Book of Songs that says: A quiet girl is a girl, as long as I am in the corner of the city. The corner is the corner of the city gate. Why do girls wait for their sweetheart here? Because the wall here is relatively high, it can block the line of sight and is relatively private, so it is a good place for dating. In the Song Dynasty, all the city walls began to be built with bricks, and the four walls of Tokyo Imperial City were finally built with bricks. Of course, they were rammed with earth. There was still no progress in the Yuan Dynasty. The walls of the capital Beijing are still rammed earth. Now there is a place in Beijing called Beitucheng, which is its ruins. How pathetic is it? On rainy days, you have to rely on reeds to keep out the rain, otherwise the wall made of this soil may collapse if there are too many. Since the Ming Dynasty, city walls all over the country have been built with bricks on a large scale. When you see a brick wall in the future, you should realize that it is definitely not ancient, and it was probably built after the Ming Dynasty. There are many advantages to wrapping or repairing a wall with bricks. Besides being rain-proof, the brick wall is bare, so it is not easy for the enemy to climb it. In addition, in ancient times, there was a tool called a trebuchet. If it is an earth wall made of rammed earth, the trebuchet throws too many stones and it is easy to collapse. In the Song Dynasty, they even shot arrows at the earth wall, and then let the siege soldiers grab the arrows and climb the wall. Brick walls are much more resistant to beating!

The role of city walls in ancient military defense is self-evident, especially in those frontier military areas. Take Datong as an example. It is a nine-border city in the Ming Dynasty. Ming Yingzong orthodox fourteen years, that is, AD 1449, Ming Yingzong led the Northern Expedition. Due to the blind command of eunuch Wang Zhen, hundreds of thousands of Ming troops were first defeated by the troops led by Mongolian Walla Department (Walla leader) and Ming Yingzong was captured. First, Ming Yingzong was kidnapped. After Datong, he wanted to blackmail a sum of money. He sent people to the big city to ask for gold coins, and he wanted to take the opportunity to attack when the emissary entered. The Ming defenders in the city didn't even open the door, so they hung up the messenger and didn't give the first army a chance to attack. I must take my troops away first. Soon, Valla's cavalry came again. Deng Guo, commander of Datong, used a trick of pretending to surrender to lure Vara's cavalry into the urn. As I said before, the urn is a circle of walls around the gate. After the enemy came in, the Ming army ambushed on the city wall in advance, shooting arrows and throwing stones, and the Vara cavalry was defeated. Then, Deng Guo asked the soldiers to pretend to be ordinary people, take poisonous wine, pork and mutton, gold and silver tin foil and other things to the suburbs, and pretend to go to the grave. Vala cavalry fell into the trap again, rushed over to grab wine and meat, ate it, and died a lot. The big cities in the front line of border defense have once again resolved the crisis. It is conceivable that Datong could hardly resist the repeated attacks of Mongolian cavalry without tall city walls, crocks and solid gates.

For ordinary cities in the mainland, the defensive function of the city wall is also enormous. After the Taiping Heavenly Kingdom troops occupied Nanjing, they took it as the capital and called it Tianjing. Ceng Guoquan, Zeng Guofan's younger brother, led the Xiang army to fight outside Nanjing for several years, but he could never attack Nanjing. Finally, it began to dig tunnels. 1864, the Xiang army spent five days digging tunnels under the Nanjing city wall. The result was discovered by the Taiping Army. They bombed and set fire with guns, and more than 400 Xiang troops in the tunnel were wiped out. In the end, the solid Nanjing city failed to resist the tunnel warfare of Xiang army. They dug many tunnels. Finally, after three years of tongzhi, they succeeded once. With 30,000 kilograms of explosives, the walls of Nanjing were blasted, Xiang troops swarmed in and Nanjing was conquered. Of course, this is done in modern times with powerful gunpowder.

In ancient times, in the face of solid city walls, what other methods were there to attack the city? The first is to hit the city gate. There is a tool, also called a car, which has several wheels and can be pushed. On it, a thick log is driven, the front of which is covered with metal, and soldiers can push it into the city gate. The enemy will shoot arrows from overhead, so they will put a board on the roof. What if the enemy burns the board? The boards are also covered with mud to prevent fire. Once the city gate is breached, our army can rush into the city.

Besides attacking the city gate, the other is attacking the city wall. I mentioned the trebuchet before. In the era of cold weapons, there were no cannons, and most of the city walls were earth walls. The trebuchet is very powerful. 1 126, Jin Bing attacked Kaifeng, the capital of the Northern Song Dynasty. Overnight, more than 5000 trebuchets were placed outside the 50-mile-long Kaifeng city wall and attacked at the same time. The stone bullets fired by 8 Jin J were so dense that Song Jun, who was guarding the city, could not stand on the wall and had to retreat to the gate. How exaggerated is it? A stone can't be found on the outskirts of Kaifeng, which was used by Jin Jun to attack the city wall. In addition, we often see climbing over the city wall with a ladder in film and television dramas. After the Tang and Song Dynasties, soldiers rarely used ladders to run to the bottom of the city wall. They greatly improved the ladder, which is similar to a car. The ladder is placed on the car, which is very high and can be folded. When the car reached the bottom of the city wall, the ladder was opened and climbed up. Climbing a ladder is the most dangerous. The defenders in the city shot arrows, threw stones and cut spears, and they must have been the first to climb the enemy city head in ancient times. The ladder can't be attacked, and the ancients have a way. At that time, there was a tool called Jinglan, which was a siege weapon more than ten meters high. It is said that Mozi invented it. It is actually a mobile arrow tower, which is several stories high, even higher than the defenders standing on the wall. It doesn't need to look up at the enemy, so it can attack the enemy on the wall from above.

What if the city wall is really difficult to conquer? The story about the flood of the Seven Armies in Romance of the Three Kingdoms. Yes, water attack is also a routine operation of ancient siege. In September of the fifteenth year of Chongzhen, Li Zicheng led the rebel army to attack Kaifeng for the third time, but it couldn't be fought for four consecutive months. So they dug Majiakou section of the Yellow River and irrigated Kaifeng with river water. Kaifeng was flooded, causing numerous deaths and injuries, and the whole city became a dead city. However, the technical requirements of water attack are very high, and people who understand water conservancy are needed, otherwise they will lose their hands and suffer losses. In l23 1 year, the Mongols besieged Guide City of the Jin Dynasty, and decided to attack by water. Because it was a dry season, the Mongolian army didn't know the terrain and water conditions. The flood did not flood the city, but formed a barrier outside the city, and built a moat for the defenders free of charge, making it more difficult for Mongolian fighters to attack. In short, it is not easy to defend the ancient city wall, and it is also difficult to attack the city.