The origin of six doors
The ancient yamen opened six more doors, showing majesty and style. The origin of the name of Six Doors is related to the layout of ancient yamen. Ancient architecture is bound by etiquette and law. The gate of the yamen is a building with a roof, and there are only three bays, regardless of the level. Two black painted doors were installed in each bay, which added up to six doors, so all the government offices at that time also had six doors.
Six doors first appeared in the early Tang Dynasty, when the six-part system had been established, but there were still many unstable factors in society. "Six Doors" was set up in the Ministry of Punishment mainly to secretly investigate the remnants of the Sui Dynasty and secretly arrest them, but with the stability of society, the organization also withdrew from the historical stage.
There are six doors in the Song Dynasty, whose main functions are similar to those in the Tang Dynasty, but the difference is that the six doors in the Song Dynasty belong to the Emperor of the Song Dynasty and not to the Ministry of Punishment. Their function is to investigate and arrest some things and people who can't be on the stage for the emperor.
During the Wanli period of the Ming Dynasty, in order to deal with some major cases, a secret organization was established, consisting of killers, spies and others. This organization is very organized and fierce, and there are many legends about them among the people, but with the demise of the Ming Dynasty, this organization also disappeared.