When did eunuchs begin to exist? What is the origin?

In China, the word "convex knife" appeared in Oracle Bone Inscriptions in Shang Dynasty, and its meaning was similar to castration, indicating that people were castrated at that time; But there is no record that they are court attendants. The use of eunuchs began in the records of the Western Zhou Dynasty. In Zhou Li, there is a saying that "the palace is kept inside, and it is rejected by humanity". At that time, eunuchs were regarded as "temple people", "inner vertical people" and "people", but their numbers were small and their status was low. They are only responsible for handyman, messenger and so on, which is a kind of retainer. With the development of autocratic monarchy, in the Warring States and the Qin Dynasty, the number of prisoners increased greatly, and the institutions that used eunuchs also increased, and eunuchs began to take power.

In the Han Dynasty, people who waited on the emperor were called "officials" or "eunuchs". It is said that the name comes from a constellation called "Guan" in the vault next to the Emperor of Heaven. By the Eastern Han Dynasty, all eunuchs had to use eunuchs, and it was the first time that a large-scale eunuch came to power. Later, in the late Tang Dynasty, large-scale eunuchs came to power again. As for the term "eunuch", it first appeared in Liao Dynasty. Originally, it was called a senior government position, not necessarily appointed by eunuchs. In the Ming Dynasty, there were twelve prisons and twenty-four yamen in the imperial court, and the leaders were eunuchs, all of whom were eunuchs. So "eunuch" became the title of senior eunuch, and later became the general name of eunuch.