From the late seventeenth century onwards, Chinese merchants, known as Hongs, managed all trade in the port. In 1760, by order of the Qianlong Emperor, they became officially sanctioned as a monopoly known as the Cohong and operated from the Thirteen Factories located on the banks of the Pearl River outside Canton. Thereafter Chinese merchants dealing with foreign trade acted through the Cohong under the supervision of the Guangdong Customs Supervisor, informally known as the "Hoppo", and the Governor-general of Guangzhou and Guangxi.