The first function of concubines is to carry on the family line. There is a saying in ancient times that there are three unfilial sons, and there are no descendants in ancient times, which can be said to be a very big mistake. Because the ancients paid attention to the need for someone to worship after death, and this kind of worship is generally their own descendants, mainly sons. If there is no son, it means that there is no one to worship after death. It's like a ghost. So if a man's main office has no sons or descendants. Many men will marry concubines. This is not only what you want to achieve, but also the pressure of the whole family.
Generally speaking, concubines have a low status. Some are similar to domestic maids. Not only have to bear the task of having children, but also need to do a lot of housework. But if concubines really gave birth to children, their status in the family can be said to be relatively high. But according to the ancient tradition, many times, the son born must be adopted to the main house, and the main house is called the mother, so that he can have the right to inherit. Although cruel, the life after concubines is still good. However, if the concubines don't have children, the end will be miserable.
For men at that time, concubines were really their personal belongings. These concubines are transferable. Sometimes men give concubines to friends or subordinates. Please or win them. At this time, concubines really became playthings. This is why many men marry concubines. It can be said that concubines really have no status or power.
But this kind of situation appeared more in the early feudal society, and it was very rare in the later period. Being deeply influenced by Zhu Cheng's Neo-Confucianism in Ming and Qing Dynasties, chastity is more important. So most of the concubines at that time were single-minded. But it is also a kind of torture for them.