From xirong and northern di in the pre-Qin era, to the Xiongnu, Turks, and Rouran later, and then to the Khitans, Jurchens, and Mongols after the Tang Dynasty, it has always been an important task for the Central Plains Dynasty to resist the large-scale invasion of the northern nomadic tribes.
In ancient times, the nomadic people did not go south to wage war after eating enough to support themselves, but indeed because of the need for survival, the Central Plains could survive by farming and developing handicrafts, but the grasslands in the north lacked such conditions.
Climatic conditions, suitable for nomadic farming is roughly bounded by a 400 mm isoprecipitation line, divided into nomadic civilization areas and farming civilization areas, on the north side of this equal precipitation line, precipitation is relatively small, the altitude is relatively high, and the local environment is not suitable for farming in ancient times.
Today, scientific and technological intervention is okay, but in ancient times, the Mongolian plateau was doomed to be unable to produce grain.
In order to survive, the people of the northern steppes made a living by hunting and grazing, forming a nomadic people.
Most of the Mongolian plateau is a nomadic ethnic group, and like in the northeast, there are semi-nomadic fishing, hunting and semi-farming civilizations, but in their lives, farming accounts for only a small part, not the main body, so it still belongs to the nomadic ethnic group.
Relying on the sky to eat, often can not eat in ancient times, whether it is farming or nomadism, basically the degree of human intervention is very low, often depends on the sky, if the wind and rain are smooth, naturally there is no problem, but I am afraid of natural disasters.
The Mongolian plateau is close to the heart of Siberia, where it is dry and rainy all year round, and drought is commonplace.
Nomadic people live by water and grass, and once they encounter drought, then the cattle and sheep herds will have no food, causing huge losses.
Farming areas can store grain, but once the cattle and sheep on the grasslands freeze to death and starve to death, they are completely useless, and in the winter, the nomadic people will go hungry, and survival will become an extremely huge problem.
Trade exchange, the status is not equal in the pre-Qin period, in fact, the boundaries of nomadic farming are not clear, even in the Central Plains, are nomadic ethnic groups and farming groups mixed together, today's Henan, at that time also lived a large number of Rongdi.
In the era of mixed habitation, the two sides could exchange their own needs, but later the nomadic tribes were expelled to the north, and there was a boundary between them.
For agricultural civilization, cattle and sheep are dispensable, but for nomadic groups, salt, rice, tea, and cloth are necessary for life.
In this very unequal situation, the Central Plains Dynasty was not interested in trade exchange at all, which also triggered a contradiction and conflict between the two major civilizations of nomadism and farming.
Due to the environment, the people's customs are fierce where the nomadic people live, the natural conditions in all aspects are actually not good, it is impossible to cultivate, even if the grazing has to change the pasture to find water, and the winter is cold and long, very difficult to survive, without tenacious vitality can not survive.
In this case, the steppe people have developed a brave and aggressive character, and only the strong can survive.
At that time, the grassland did not talk about moral etiquette, everything was based on survival first, and everything was dominated by fist strength.
When in contact with the civilization of the Central Plains, even if there is a request for people, the grasslands often think of relying on force, rather than sitting down and talking, and because of this, nomadic groups often go south to start wars.
From the pre-Qin and Inu Rong into the ho capital, to the Ming Dynasty during the Wara, Chahar and so on has been tossing and turning, for more than two thousand years, the nomadic ethnic groups often went south, becoming a huge problem in the Central Plains, but also difficult to solve.
The root cause of this situation is that the conditions on the grasslands are too harsh, and the nomadic people have to survive by conquest.
Many nomadic groups that enter the farming areas have gained a good environment and naturally abandoned their original way of life.
On the whole, nomadic people like to wage wars, mainly because of the influence of the living environment, which not only makes them form a fierce and martial personality, and naturally likes to use force, but also makes them have to rely on external plunder to obtain survival resources.