The emergence of the post of imperial envoy was related to centralization of authority in Ming and Qing Dynasties. Zhu Yuanzhang abolished the post of prime minister in order to completely control power in his own hands. The Qing dynasty continued the practice of the Ming dynasty, which led to the unprecedented concentration of administrative power in the hands of kings. Imperial envoys came into being to help the emperor deal with local affairs temporarily. In order to facilitate the imperial envoys to handle government affairs flexibly in the local area, the king will grant the imperial envoys the privilege of temporary arbitrariness, so meeting the imperial envoys is like meeting the emperor. When necessary, the king will also grant the imperial envoys the privilege of mobilizing troops, but this is usually rare. Because the court is very cautious about the power to dispatch troops. They know that force is a double-edged sword, which will threaten the stability of the ruler's power if it is not used well.
Only under certain circumstances, imperial envoys will be granted the power to dispatch troops. For example, since 1864, the vast khanates in Central Asia and Russia have successively occupied large areas of Xinjiang. 1875 left to recover Xinjiang. At that time, she was granted the power to command and dispatch the three armed forces by Cixi. It is precisely because of his absolute leadership over the army that Zuo was able to successfully recover Xinjiang. In addition, Lin Zexu was awarded the status of an imperial envoy and had the power to send naval officers to Guangzhou to take charge of the smoke. Then the famous opium destruction event happened in Humen.
It can be seen that among the privileges enjoyed by imperial envoys, it is very important to mobilize the strength of the army. Unless there is a war and some extreme events, it will not be awarded easily.