Before and after the Han Dynasty, honesty was complementary, which meant assistance, while physiognomy represented appearance and conduct. Prime minister means the emperor's dignity and moral assistance. In other words, the prime minister is a person who is used to ensure that the emperor can have enough morality and dignity to control all the officials, people and soil in the world. Used as a position, indicating that one person is below and ten thousand people are above. But the words of the Empress Dowager or the Empress Dowager are often more useful than those of the emperor, so the role of the Prime Minister is only auxiliary, and there is no right to assist the government. In addition to reporting to the emperor, the prime minister needs to ask the harem for an imperial decree most of the time. Especially in the Han Dynasty, before the Emperor Wu of Han Dynasty destroyed the Dou Wang Sun, the imperial seal was held by the Empress Dowager, and the Prime Minister was the nephew of the Empress Dowager. In any case, the post of prime minister itself is the highest spokesman under the emperor.

Needless to say, in the Qin dynasty, there was a rule in the Han dynasty that a duke who had not made military achievements could not be a prime minister.

After the Han dynasty, due to the cancellation of the policy of consorts participating in politics, the prime minister was able to play a greater role, and Cheng Xiang's post after the Sui Dynasty could be performed on behalf of the emperor. Before that, it must be carried out by eunuchs holding pens. Of course, the rights of the prime minister were adjusted in subsequent dynasties, but the changes were not great.

As for the imperial envoys, the Qin dynasty has not yet appeared, and I don't know when it first appeared. I only know that it existed in the Han dynasty. So just now, it was mainly explained by the situation in the Han Dynasty. At that time, the superficial meanings of Qin characters and Yu characters were basically the same. However, the usage is different. Qin was mostly used by the emperor himself, mostly in the case of "execution", while Yu was mostly used in the palace, mostly in the case of "use" It's like the Royal Guards are used to protect the palace, while the Royal Guards are specially used to protect the emperor. This is different from the explanation of later generations. However, the significance and role of the imperial envoys themselves have not changed, that is, they are people who travel for the emperor. This imperial minister is a post, but it was temporarily appointed by the emperor and automatically cancelled after completing the task. The grade was also temporarily decided by the emperor. Generally, it will not be lower than five products, but it will never be higher than two products. If the imperial envoys need to deal with officials of more than two ranks, they need to stamp other official positions on the imperial edict and use them at the same time. If the imperial envoys need to decide the rewards and punishments of higher-ranking officials temporarily, they need to write the word "Lian". Otherwise, it has always been a great sin to kill five or more officials of the imperial court and nine families privately. Only parties below level 5 are within the authority of the imperial envoys. After the Tang Dynasty, the actions of imperial envoys were more restricted.

So specifically, the imperial envoys themselves are smaller than the prime ministers. Even after the Tang Dynasty, the left and right prime ministers were divided. The lowest prime minister was not lower than the second class, but still higher than the highest rank of the imperial envoys themselves. However, because the imperial envoys were personally appointed by the emperor and represented the authority of the emperor, the prime minister also needed to be polite. Even on some special occasions, it is said that imperial envoys are junior officials. In addition, the functions of imperial envoys are also temporarily assigned by the emperor, so it is hard to say that a first-class cabinet official will not be awarded an imperial envoy below second-class. So there can be many kinds of statements, depending on the situation at that time.