Why did the Xiongnu popularize the system of inheritance marriage in which a son marries his stepmother and a brother marries his sister-in-law or brother-in-law?

Sima Qian's "Records of the Grand Historian" clearly records the marriage system of the Huns, which is the system of inheritance marriage, the content of which is: when the father dies, the son marries his stepmother, who is not related by blood, and when a brother dies, the remaining brothers marry the wives they left behind (sister-in-laws or daughters-in-law), which is incomprehensible to the Han people.

In fact, not only Xiongnu has this kind of inheritance marriage system, almost all nomadic people appeared in Chinese history have this system, such as Xianbei, Zoran, Turkic, Mongolia and so on, have this custom, this system can be called the characteristics of the nomadic people, then the question comes, why the nomadic people will appear this kind of inheritance marriage system?

The nomadic people represented by the Huns have three main very characteristic customs:

One, moving with the water and grass, without fixed residence.

This is a typical feature of the nomadic people, nomadic people do not cultivate the land, their main way of life is to graze and hunt, grazing and hunting need to keep changing places, it is not possible to stay in one place for a long time, otherwise livestock have nothing to eat, a place of prey is finished, there will be no prey, has been constantly to maintain a kind of nomadic life everywhere custom.

Under the influence of this way of life, the Xiongnu were in an absolute male-dominated society, where men were needed for hunting, for foreign wars, and for the defense against natural and man-made disasters, and where women's main task was to give birth to children, and also to do what they could, such as feeding the livestock, and where women's status was extremely low.

Secondly, there was a need for constant foreign wars.

Hungarians and other nomadic people due to nomadic life practices, so the ability to withstand natural disasters in nature is very weak, as long as a heavy snowfall or severe cold season, will lead to a large number of population and livestock freezing to death, once this natural disaster occurs, the Huns can not live, they have to be organized in foreign wars, by looting and plundering, to seize the means of living of others with the wealth and population.

For example, the war of Xiongnu against Han Dynasty, although there is a peace between Han and Xiongnu, but still often war, Xiongnu repeatedly violated the borders of Han Dynasty, the main thing is to loot things, wealth, and population, in order to replenish their own losses suffered from natural disasters, if you don't start a foreign war, Xiongnu in the face of natural disasters, it is very difficult to survive.

In addition to external wars, the Huns also had constant internal wars, the entire society of the Huns was a primitive tribal alliance structure, relying on blood and status to form many different tribes, when the Huns had a tribal strongman appeared, its internal is unity, once there is no, its tribal lord is divided, and will be at war with each other.

For example, during the time of Emperor Xuan Di of Han Dynasty, Xiong Nu was divided into five monarchs who fought for the throne, and there were constant wars between them. Later, Xiong Nu was divided into the South Xiong Nu and the North Xiong Nu, and the North Xiong Nu was defeated by Han Dynasty and fled to Central Asia, and the South Xiong Nu defected to the Han Dynasty, and its interior was not ironclad, and internal strife occurred at any time.

Not only the Xiongnu, later the Xianbei, Turkic, Mongolia is also so, Xianbei has five different surnames of the tribes, often war with each other, the Turkic is divided into Western Turkic and Eastern Turkic, also often war, the Mongolian empire founder Temujin did not unify Mongolia before, its internal is also divided.

The nomads, represented by the Xiongnu, had not only internal wars, but also external wars, and the constant wars made it impossible for the nomadic population to grow rapidly.

Thirdly, the population was not large.

If you look at the map, the land area occupied by the nomads has always exceeded that of the Han people, but in terms of population, the nomadic population of all dynasties has been much smaller than that of the Han people, or even less than one-tenth of the population, and the nomadic way of life could not carry a larger population.

The historical population of the Xiongnu was at most two to three million people, while the Han Dynasty of the same period had at least 20 to 30 million people, and the Western Han Dynasty had a population of more than 60 million people in its heyday, so the population of the Xiongnu was just a fraction of the Han people of the same period.

Even the Turks and Mongols had no more than 3 million people in their heyday, and far fewer than the Sui and Tang dynasties and the Southern Song dynasty, which had populations of more than 80 million, making the nomadic population far too small.

The three characteristics of the nomadic people represented by the Huns all lead to one problem, the population problem, the nomadic people's population growth rate is very low,especially the number of male population.

So the biggest development problem of the nomadic people is how to increase the population, and the system of receiving and marrying is a solution to the population problem that the nomadic people have come up with and formed a system for in the long term practice of life.

The Records of the Grand Historian recorded that the Xiongnu revered the strong and looked down on the weak, good food was given to the strong and the old and weak ate the leftovers, the best opposite of the traditional virtues of the Han Dynasty, the reason why the Xiongnu had such a custom was their way of life dictated by the fact that in the constant nomadic pastoralism, in the foreign wars, and in the defense against natural and manmade calamities, only the strong could have more power to protect the whole tribe and thus survive.

Looking at the Huns' system of receiving and marrying, when the father died, the son would marry his stepmother, who was not related by blood, and if he didn't? That would be the widowed and orphaned mother. The smallest unit in the Huns was the tent, equivalent to a Han Chinese family, a similar concept to the later Turkic tents and yurts, a tent was a small family living together.

If a man dies in a small family of one tent, how do the widows and orphans live? In the midst of constant nomadism, without men, widows and orphans may not even be able to drive their own livestock away, let alone prepare their own family for nomadism, and in the midst of internal and external wars, widows and orphans are even less able to survive.

But one can't drive the orphans and widows away from one's own belongings, then the population will be even smaller, so the best way is to have a man come out and marry the widowed mother, and the orphan becomes the man's son, so that the man becomes the master of the house in a tent family, and likewise the man marries the widowed mother and continues to have a population, which is a one-two punch, and is the biggest effect of the Huns' collection of the successor marriage system.

When a brother dies, the remaining brother marries his sister-in-law or brother-in-law for the same reason, some families are fathers and sons and some families are brothers and sisters, no matter whether they are fathers and sons or brothers, in order to protect the orphans and widows and to continue to reproduce the population, so the system of inheritance marriages came into being.

This is a product of history and a characteristic of the nomadic people, which is incomprehensible to the Han Chinese, but the nomadic people are using the correct experience of their own people's historical development. If there is no system of receiving succession marriage, the nomadic people's character may be even less.

In addition to this, the Huns also take women as a tool for procreation, if the father died and there is no son, or brother died and there is no brother, the wife they left behind will have other men to marry, in order to is not to waste any opportunity to procreate the population, this is the nomadic people left behind the primitive social customs, is a specific product of history, there is a certain degree of reasonableness.