Why was foreign trade with Britain limited to Guangzhou during Qianlong’s reign?

During the reign of the Qianlong emperor, foreign trade with Britain and other Western nations was restricted to the port of Guangzhou (Canton) primarily to tighten government control over foreign commerce and maintain the established Canton system.

In 1757, the Qianlong emperor issued a decree explicitly confining all foreign trade to Guangzhou in response to British attempts to expand their commercial activities to ports in North China. This policy was rooted in the Qing dynasty's broader approach to foreign relations, which was governed by the tributary system. Under this worldview, the emperor viewed China as the superior "Central Kingdom," and foreign powers were expected to interact with the empire as vassals rather than as equal diplomatic or commercial partners.12

By centralizing trade in one location, the Qing government could strictly regulate foreign merchants, subject them to the oversight of the cohong—a guild of officially authorized Chinese merchants—and minimize direct contact between the two governments. This arrangement allowed the state to maintain stability and control while managing the flow of goods like tea, silk, and porcelain.13