1685, the Kangxi emperor legalized private maritime trade along the coast, establishing a series of customs stations in major port cities. The customs station at Canton became by far the most active in foreign trade; by the late Kangxi reign, more than forty mercantile houses specializing in trade with the West had appeared. The Yongzheng emperor made a parent corporation comprising those forty individual houses in 1725 known as the Cohong system. Firmly established by 1757, the Canton Cohong was an association of thirteen business firms that had been awarded exclusive rights to conduct trade with Western merchants in Canton. Until its abolition after the Opium War in 1842, the Canton Cohong system was the only permitted avenue of Western trade into China, and thus became a booming hub of international trade by the early eighteenth century. By the eighteenth century, the most significant export China had was tea. British demand for tea increased exponentially up until they figured out how to grow it for themselves in the hills of northern India in the 1880s. By the end of the eighteenth century, tea exports going through the Canton Cohong system amounted to one-tenth of the revenue from taxes collected from the British and nearly the entire revenue of the British East India Company; in fact, until the early nineteenth century tea, comprised ninety percent of exports leaving Canton. Revenue The recorded revenues of the central Qing government increased little over the course of the 18th and early 19th century from 36,106,483 taels in 1725 to 43,343,978 taels in 1812 before declining to 38,600,570 taels in 1841, the land tax was the principle source of revenue for the central government with the salt, customs and poll taxes being important seconday sources. Following the Opium wars and the opening of China to foreign trade and the mid-century rebellions against the Qing 2 further important sources of revenue were added the foreign maritime customs revenue and the likin revenue though only 20% of the likin revenue was actually given by the provinces to Hu Pu (board of revenue) in Beijing the rest remaining in provincial hands, the Hu Pu also managed to raise some miscellaneous taxes and increased the rate of the salt tax these measures doubled revenue by the late 19th century, this however was insufficient for the central government which was facing numerous crises and wars during the period and 9